Evaluating the Instructional Efficacies of Conceptual Change Models on Students’ Conceptual Change Achievement and Self-Efficacy in Particulate Nature Matter in Physics

This study determined the efficacies of cognitive conflict and 5E instructional models on students’ conceptual change achievement and self-efficacy in particulate nature of matter concepts in physics. In this study, non-equivalent groups quasi-experimental design was used. A sample of 195 senior secondary school year 1 students (SSI) with an average age of (M = 14.64, SD = 3.34) was used. Particulate Nature of Matter Conceptual Change Test (PNMCCT), and Particulate Nature of Matter Self-Efficacy Scale (PNMSES) were used to collect data. The SES was adapted and consists of 30 items of four-point Likert-type. A trial test was done on 20 SS1 physics students using the validated instrument. The estimate of internal consistency of .86 and a temporal stability of .99 were obtained for PNMCCT while an estimate of internal consistency of .71 was obtained for PNMSES. Before treatment, the initial conceptual change achievement and self-efficacy of the subjects were established using PNMCCT and PNMSES. After the treatment, the PNMCCT and PNMSES instruments were administered to the subjects as a posttest. Mean was used to answer the research questions while analysis of covariance was used to test the hypotheses at a 5% level of significance. The result showed that students’ conceptual change achievement and self-efficacy were significantly enhanced after exposure to 5E instructional treatment than that of cognitive conflict. Thus, it was recommended that the 5E instructional model should be adopted by physics teachers for the effective improvement of physics students’ self-efficacy in schools.


Research Background and Problem
Science has become an indispensable tool in the development of every nation across the globe. No nation that wants to remain relevant in the socio-economic domain will not do without learning in schools. The importance of science is evident, especially in the face of modern technological innovations. To achieve this, one has to rely on the knowledge and understanding of physics, its theories and principles, and their applications to everyday life. Reports have shown that academic achievement in science, especially physics among students has been below average (Akanbi et al., 2018;Gana et al., 2019;Ugwuanyi et al., 2019). Achievement in physics examinations by students is on a low trend compared to other science subjects like biology and chemistry .
In the face of this challenge, Ugwuanyi et al. (2020) opined that the major cause of the poor academic achievement of students in physics can be linked to teachers' inability to use innovative instructional models in the 21st-century classroom. Examples of such innovative instructional models include 5E and cognitive 1 University of Nigeria, Nsukka, Nigeria 2 University of the Free State, Bloemfontein, South Africa conflict instructional models. These two innovative models are both constructivist models which are studentscentered instructional models. This opinion was validated by Aktas x (2012) who stated that the choices of instructional models that are students-centered are effective and useful in transforming aims into behaviors. In this circumstance, the instructor acts as a co-explorer, encouraging learners to question, confront, develop their own ideas and viewpoints, and reach conclusions. It is, therefore, justifiable to compare the effects cognitive conflict and 5E instructional models as they are both constructivist models and are similar in steps and implementation procedure.
The 5E model consists of five cognitive stages of learning cycles that comprised engagement, exploration, explanation, elaboration, and evaluation (Bybee et al., 2006). On the other hand, Cognitive conflict is initiated when a student experiences contradictions with his or her prior knowledge. Cognitive conflict is said to occur when a student's mental structure is distressed by experiences known as anomalous data that do not conform to their current knowledge (Foster, 2011). In these models, the students are actively engaged. To engage students actively, learning has to be related to the real environment of students and provide an opportunity for the students to interact in the learning process (Saputro et al., 2020). The environment of the learner includes either his or her cognitive and affective variables. Hence, for an individual to construct knowledge, cognitive intelligence is needed by such an individual which self-efficacy can impact how and what knowledge is constructed (Fitriani et al., 2020).
Self-efficacy, as an affective variable, influences students' activity choices, goal orientations, learning effort, and achievement in a variety of ways. The term ''general self-efficacy'' refers to a person's entire confidence in his or her ability to succeed (Riopel, 2019). According to Arı and Sadi (2019), self-efficacy refers to an individual's belief in his or her ability to overcome obstacles when confronted with a circumstance. It has been stated that self-efficacy beliefs are subject and content specific (Bandura, 1997). Self-efficacy is individuals' judgments of their capabilities as a result of the reciprocal interplay of cognition, behavior, and environment. According to a study, pupils' academic self-efficacy is on par with the national average (Thompson & Verdino, 2018). As a result, it's critical to figure out how to boost pupils' academic self-efficacy. This is due to the fact that selfefficacy is a critical psychological element that determines academic motivation, task persistence, learning success, and job choice (Thompson & Verdino, 2018;Webb-Williams, 2018).
Students differ in self-efficacy measures. Alhadabi and Karpinski (2019) reported that low self-efficacy among students is linked to dishonest academic behavior. Therefore, one could suggest that self-efficacy among physics students may be associated with their physics concepts learning and generally affects their academic achievement in physics. Self-efficacious students will set higher goals and have a high degree of commitment to more challenging goals. Through the use of an appropriate instructional model students' self-efficacy can be improved. Hence, Wahyudiati et al. (2020) stated that teachers should strive to promote students' selfefficacy using instructional models. This confirms the importance of the instructional model used by teachers in promoting students' self-efficacy believes.

Theoretical Framework
This study is anchored on the work of the social cognitive theory of Bandura (1986). According to this idea, human conduct is influenced by a combination of three variables: personal characteristics such as beliefs, behavior, and environmental effects (Bandura, 1986). This theory combines behaviorist and cognitive perspectives on learning. Learning is a product of the learner's interplay of cognitive, behavioral, and environmental elements, according to the notion. For instance, an individual's self-efficacy is linked to his or her personal and behavioral factors. Again, the thought process of individuals influences their behavior. Therefore, when this theory is applied to concept learning in physics, it suggests that personal belief may influence conceptual change and consequently affects their general learning outcomes (Bandura, 1989).
Secondly, the interplay between personal and environmental factors maintains that the belief system and cognitive competencies of the individual could be affected by social influences. Therefore, during physics instructions, social persuasion in form of positive feedback will produce desired changes in students' beliefs about their ability. The last relationship is the interplay between behavior and environmental factors. This relationship suggests that behavior is formed and influenced by the environmental factors of the learner. In the case of physics students, active learning and interactions with peers help improve students' efficacies to the carryout learning task. Also, positive feedback by teachers motivates students during learning and helps them achieve the stated goals.
Given this theory, self-efficacy belief plays a vital role in determining physics students' choice of instructional activities, goal orientation, preparation to continue and complete challenging tasks (Bandura, 1997). Therefore, students behave in certain ways that they believe to themselves will produce results that they value. Additionally, it means, therefore, that the self-efficacy belief of physics students may affect their physics concepts learning and generally their academic achievement in physics. Self-efficacious students will set higher goals and have a high degree of commitment to more challenging goals. Therefore, this study is focused on investigating the efficacies of instructional models on students' self-efficacy within the content of particulate nature of matter.

Research Focus
Self-efficacy is a fundamental ideal in Bandura, social cognitive theory. The belief in one's ability to succeed is referred to as general self-efficacy (Riopel, 2019). According to Arı and Sadi (2019), self-efficacy refers to one's belief in one's ability to complete a task in a specific situation. Similarly, Oner Armagan et al. (2016) defined self-efficacy as a person's assessment of his or her own competence to carry out events and complete a task successfully. Operationally, self-efficacy is individuals' judgments of their capabilities as a result of the reciprocal interplay of cognition, behavior, and environment. Students' self-efficacy involves students' abilities to organize and execute learning tasks required to achieve stated learning goals.
Self-efficacy as an affective variable is a vital construct that can impact how and what students learn. This is because it concentrates their attention on their perception of their ability to learn. Self-efficacy comes from four different places. Mastery learning, vicarious learning, social persuasion, and emotional response interpretation are among them (Bandura, 1977). According to many reports, self-efficacy measurement is task and domain specific (Bandura, 1977(Bandura, , 2006Sawtelle et al., 2012). The purpose of measuring self-efficacy is to improve students' ability to accurately forecast their own learning. Carrying out a task successfully can increase self-efficacy while failure to perform a task successfully lowers it (Bailey et al., 2017). Physics Self-Efficacy and Identity Survey by Kost-Smith (2011), Sources of Self-Efficacy in Science-Physics by Fencl and Scheel (2005), and Physics Learning Self-Efficacy by Suprapto et al. (2017) have been used to measure self-efficacy among students in physics.
Research reports have shown a different link between students' self-efficacy and their achievement in physics. These reports showed a positive relationship between self-efficacy and academic achievement (C xapri, 2013;El-Adl & Alkharusi, 2020;Marsh et al., 2015;Njega et al., 2019;Oyelekan et al., 2019;Yerdelen-Damar & Pes xman, 2013). Similar research found a substantial positive association between learners' academic achievement and their self-efficacy, regardless of content (H€ useyin et al., 2018;Nwaukwa et al., 2019;Osenweugwor, 2018;Oyuga et al., 2019). Therefore, self-efficacy is a strong predictor of academic achievement with different content. There is a need to focus research on instructional models that may promote students' self-efficacy and academic achievement in different content in physics. There are many such instructional models, but cognitive conflict and 5E instructional models were used.
5E instructional model is anchored on the constructivist theory of learning. This is a theory where individuals construct knowledge from personal experiences. The 5E model consists of five cognitive stages of learning cycles. These learning cycles comprised engagement, exploration, explanation, elaboration, and evaluation (Bybee et al., 2006).
These stages of learning cycles and their activities include: (1) Engagement-during the engagement stage, the teacher assesses the learners' prior knowledge and assists them in becoming engaged in a new concept through the use of short activities that promote curiosity and elicit prior knowledge by making connections between past and present learning experiences. (2) Exploration-exploration of experiences provides students with a common basis of activities in which they can identify their existing notions (i.e., naive conceptions), processes, and skills, as well as encourage conceptual transformation. Learners can perform laboratory activities to help them generate new ideas, examine questions, and explore possibilities based on past knowledge; (3) Explanation-the explanation phase directs students' attention to a specific component of their engagement and exploration experiences and allows them to exhibit their conceptual understanding, process abilities, or behaviors. This phase also allows teachers to directly present a concept, technique, or skill that will help pupils gain a better knowledge of it. (4) Elaboration-the teacher pushes students' conceptual knowledge and talents to new heights. Students gain a deeper and broader understanding, more information, and adequate abilities as a result of new experiences. Students put their knowledge of the idea into practice by participating in additional activities; and (5) Assessment-the assessment phase allows students to analyze their understanding and abilities while also allowing teachers to review students' progress toward achieving the educational goals.
Moreover, 5E Model of Instruction is focused on inquiry unlike cognitive conflict instructional model. The focus is on the students, with the teacher largely acting as a facilitator. Through open-ended inquiries, real-life experiences, guided investigations, hands-on projects, and research, students get a thorough understanding of the scientific principles given in the course. Each level of the model builds on the one before it, creating a coherent framework for lessons, activities, and units.
Studies elaborated that the implementation of the 5E instructional model positively influences students' learning. It enhances students' behavior and attitude toward science instruction (Lin et al., 2014) and develops students' creative thinking (Polgampala et al., 2016). A recent study reported that the implementation of the 5E instructional model fosters students' ability in establishing a link between scientific concepts and real events (Siwawetkul & Koraneekij, 2018). Another instructional model that may promote students' self-efficacy is cognitive conflict.
Cognitive conflict is initiated if a learner experiences contradiction with his or her prior knowledge. The cognitive conflict instructional model has been reported to be the starting point for conceptual change. In the cognitive conflict model of instructional, students' confidence in their existing conceptions is destabilized through discrepant events. This allows students to replace their inaccurate initial conceptions with scientific conceptions (Kang et al., 2010). The cognitive conflict model is used to initial conceptual change when one's beliefs, values, or behaviors do not agree with the incoming ones. The implementation of this strategy in the learning process aims to generate contradiction with the initial ideas of the students so that they are compelled to reconstruct their understanding and have the correct concept (Labobar et al., 2017).
Learners may hold conflicting ideas. However, these co-existence ideas may not create a dissonance. The cognitive dissonance model holds that contradicting cognitions act to push the learner to gain new thoughts, beliefs or modify existing beliefs (Harmon-Jones, 2017). The cognitive dissonance model maintains that when learners hold conflicting ideas a state of discomfort known as dissonance is created (Harmon-Jones, 2019). The implementation strategy of cognitive conflict in learning followthrough six steps (Orji, 2013). Orji (2013) explained that in this model, students are presented with experiments to generate students' alternative conceptions through anomalous experiments. Thereafter, students perform activities and come up with contradictions with previous conceptions. This eventually sets the students in cognitive conflict. Then the students will be allowed to discuss among themselves the result of their findings and comparing these results with their previous ideas. This enables them to exchange ideas based on their findings from the activities. At this stage, the teacher summarizes the different ideas and presents the correct ideas. Several studies have been reported on different topics where the cognitive conflict instructional model has been implemented. Such topics include temperature and heat (Madu & Orji, 2015;Orji, 2013;Orji & Madu, 2016) and courses in computational physics (Akmam et al., 2018).

Research Aims and Research Questions
This study investigated the effect of instructional models on students' conceptual change achievement and selfefficacy in particulate nature of matter concepts. Specifically, this study investigated the effects of cognitive conflict and 5E instructional models on students' conceptual change achievement and self-efficacy in particulate nature of matter. The following questions were answered (i) What are the mean conceptual change achievement scores of students taught particulate nature of matter using cognitive conflict instructional model and those taught using 5E instructional models? (ii) What are the mean self-efficacy ratings of students taught particulate nature of matter using cognitive conflict instructional model and those taught using 5E instructional models?

Ethical Approval Statement
The researchers were granted ethical approval to conduct this research by the researchers' university committee on research ethics. Besides, the participants were served with informed consent forms to fill and sign before the commencement of the experiment.

Study Participants
The sample for the study comprised 195 senior secondary school year 1 students (SSI) with an average age of (M = 14.6, SD = 3.34). These are students who have completed the 9 years compulsory basic education and are now in the first year of senior secondary education in Nigeria. This sample was drawn out of 5,312 senior secondary school year 1 physics students in 13 public senior secondary schools in Bwari Area Council of FCT for the 2019/2020 session. Purposively, the sample was drawn from two senior secondary schools in the Bwari Area Council of FCT. Each of the schools has two intact classes. The students in each of these schools were assigned to either the cognitive conflict instructional model or the 5E instructional model through simple random sampling by balloting. This implied that treatment with the cognitive conflict model has a total of 98 students from two intact classes of 50 and 48 while treatment with the 5E instructional model has a total of 97 students from two intact classes of 48 and 49 students. The following were the inclusion criteria for participants' selection: (i) must be a first-year senior secondary school student, (ii) must be in a public school within Bwari Area Council, (iii) must have passed physics in the last term before the treatment.

Instruments Validation and Reliability
The study employed two instruments: the Particulate Nature of Matter Conceptual Change Test (PNMCCT) and the Particulate Nature of Matter Self-Efficacy Scale (PNMSES). PNMCCT was adapted from Ozalp and Kahveci (2015), who created a 25-item particulate nature of matter question (15 two-tier and 10 one-tier). The PNMCCT was created to test students' knowledge on the issue of particulate matter. Some of the elements (3, 5, 6, 8, and 14) are true or false in the original text. Because true or false cannot be used to measure conceptual change, the researcher deleted these questions as part of the adaption measures. Other questions contained three, four, or five multiple-choice answers. In addition, for the present edition, the researcher adapted uniformity of the number of possibilities as well as an equal number of justifications in each of the items. To maintain uniformity, the researcher reduced the number of possibilities to four (i.e., a-d) and four justifications (i.e., 1-4). Some questions were removed from the original instrument since they did not pertain to the themes presented, while new questions were derived from other fields in which pupils have naive ideas. As a result, a total of 20 items were created based on concepts and topics about which students had no prior knowledge. The instrument is graded by matching any of the four options to the correct justification for the choice. The instrument was properly validated by test development experts and physics educators after which it was trial tested. The reliability of PNMCCT was established using Cronbach's Alpha formula after trial testing. The instrument's internal consistency index was found to be .86. Similarly, the estimation of PNMCCT's temporal stability was assessed using the test-retest method and the Pearson product moment correlation coefficient, which was found to be .99.
Self-Efficacy Scale (SES) was the instrument for the study. SES was adapted from Suprapto et al. (2017) which was designed to measure Indonesian University Students' physics learning self-efficacy. The instrument originally was presented with bipolar strongly agree to strongly disagree statements in a five-point Likert scale. The instrument was grouped into six dimensions of science content (SC), Higher-Order Cognitive Skills (HCS), Laboratory Usage (LU), Everyday Application (EA), Science Communication (SCM), and Scientific Literacy (SL). As part of adaption processes, these dimensions were removed. Also, double barreled items were removed and unclear words restructured to maintain 30 items four-point Likert scale of Strongly Agree = 4, Agree = 3, Disagree = 2, and Strongly Disagree = 1. The higher scores indicated greater physics self-efficacy. The SES comprised two sections. Section A included responses about the school and class codes of the students, while section B included 30-item responses on the self-efficacy of the student in particulate nature of matter content areas. In these 30 items, students are to tick one response option of either strongly agree, agree, disagree, or strongly disagree. The internal consistency reliability indices of the six dimensions of SES were estimates to be a = .78 for HCS, a = .81 for LU, a = .73 for EA, a = .67 for SCM, and a = .86 for SL with an overall reliability index of a = .71.
Lesson plans with cognitive conflict and with 5E instruction models were developed by the researchers. Lesson plans (see Appendices A and B) that lasted for five periods on each of the models were developed. The instrument and the lesson plans were subjected to face validation using five experts; two experts from the Measurement and Evaluation unit and two from Physics Education unit of the Department of Science Education and one in Educational Psychology unit of the Department of Educational Foundation. Specifically, in face validation, the experts were requested to check the extent to which each of the items of the instrument measures what it is expected to measure as well as the ambiguity or otherwise of the language used in writing the items in the instruments, the suitability of the items relative to the class of the students in focus and clarity of instruction to the research subjects. Copies of the lesson plans were equally face validated by the experts. The suggestions and comments of the validators were used to arrive at the final copy of the instrument as well as the lesson plans.
The researcher subjected the validated instrument to trial testing on 20 SSI students, drawn randomly from Government Secondary School Karu in Abuja Municipal Area Council (AMAC) of FCT. The data obtained were analyzed using the Cronbach Alpha formula in which a reliability coefficient of .71 was obtained.

Experimental Procedure
Prior to the start of the treatment, the researcher trained the research assistants on how to implement cognitive conflict and 5E instructional models using the prepared lesson plans. The training involved practical demonstrations of the steps involved in the two instructional models by the research assistants with a class of SS1 students in another school within the vicinity. The training also included how to administer and collect the instruments used for data collection. The training lasted for 3 days. The first day of the training was used to teach the research assistants the steps of the cognitive conflict and 5E instructional models for teaching both groups with particular attention on how to identify students' naive conceptions through the use of questions during instructions and how to use the various steps to contradict, students' naı¨ve conceptions, create cognitive conflict with the anomalous situation and how to change students' naı¨ve conceptions to scientific sound conceptions. The researcher demonstrated these steps to the research assistants and the research assistants were given the opportunity to demonstrate it by themselves. The lesson plans were used as a guide with emphasis on the steps and skills involved. The second day was used for a practical demonstration of the steps involved in the implementation of the models using a class of SS1 in another school within the locality. Feedback was provided to strengthen the research assistants' capacity to use these models and adhere strictly to the lesson plans prepared by the researcher.
The third day was spent on how to assign code to students and schools and how to administer and collect the instruments that were used for data collection. The research assistants were told that the code of each student should be written down (in the space provided in the instruments) by the students so as to remember it during the pretest and posttest exercises. The code numbers of each of the two schools that were used for the study were equally given to them. The aim of using code number for students and schools in place of students and school names was to identify scores of each student so as to trace the conceptual change of the candidate and as well ensure confidentiality. Sample of the instruments were shown to the research assistants, and ways of ticking them were equally demonstrated to them. Base on the aforementioned, the researcher was convinced that the research assistants had mastered all the procedures, raised doubts and wholly understood every step of the experiments and were ready to assist and adhere to all lesson plans prepared. SES was given to the students before the start of the treatment as a pretest to establish their initial self-efficacy before the treatment.
Thereafter, treatment was given to the students in their separate groups for 4 weeks. Group 1 was taught using the cognitive conflict instructional model while the second group was taught using the 5E instructional model. Then students in each group were given the same SES to answer as the posttest. The SES were retrieved for analysis.

Data Analysis Procedure
Mean was used to analyze the data to answer the research question while analysis of covariance was used to test the hypothesis at .05 level of significance.

Results
These results are presented according to the research question posed and the hypothesis stated.
Research Question 1: What are the mean conceptual change achievement scores of students taught particulate nature of matter using cognitive conflict instructional model and those taught using 5E instructional models? Table 1 shows that at the pretest, students who were taught particulate nature of matter using the cognitive conflict instructional model had a mean conceptual change achievement score of (M = 37.00, SD = 2.37), while those who were taught using the 5E instructional model had a mean conceptual change achievement score of (M = 36.28, SD = 2.16) This suggests that at the start, the two groups had roughly comparable self-efficacy. After the instruction, the cognitive conflict model group had a mean conceptual change achievement score of (M = 67.24, SD = 2.56) with an adjusted mean of (M = 76.20), whereas the 5E instructional model group had a higher mean conceptual change achievement score of (M = 78.02, SD = 1.62) with an adjusted mean of (M = 78.07). The difference in their adjusted mean conceptual change achievement scores shows that the group taught with the 5E instructional model had higher adjusted mean than the group taught with the cognitive conflict model.
Hypothesis 1: There is a significant difference in the mean conceptual change achievement scores of students taught particulate nature of matter using cognitive conflict instructional model and those taught using 5E instructional models. Table 2 shows the test of the homogeneity of variances of the two groups with respect to their conceptual change achievement scores. The analysis indicates that the variances are equal across the two groups, F(1, 193) = 0.561, p = .602. This is for the fact that the p-value of .602 is larger than the .05 level of significance.
Table 2 also indicates that there is a significant effect of the instructional model on students' conceptual change achievement scores in particulate nature of matter, F(1, 192) = 36.941, p = .000. This means that there is a significant difference in the mean conceptual change achievement scores of students taught particulate nature of matter using the cognitive conflict instructional model and those taught using the 5E instructional model in favor of those taught using 5E instructional model. Besides, the effect size of 0.161 means that a 16.1% variation in the conceptual change achievement scores of the students is as a result of their exposure to the 5E instructional model. This confirms that the 5E instructional model enhances students' conceptual change achievement score more than the cognitive conflict instructional model.
Research Question 2: What are the mean self-efficacy ratings of students taught particulate nature of matter using cognitive conflict instructional model and those taught using 5E instructional models? Table 3 shows the pretest and posttest mean selfefficacy ratings of the two groups in the six dimensions of self-efficacy scale as well as the overall mean. At the pretest, students who were taught particulate nature of matter using the cognitive conflict teaching model had a mean self-efficacy score of (M = 40.64, SD = 3.79), while those who were taught using the 5E instructional approach had a score of (M = 40.71, SD = 3.60). This suggests that at the start, the two groups had roughly comparable self-efficacy. After the instruction, the cognitive conflict model group had a mean self-efficacy rating of (M = 114.04, SD = 4.25) with an adjusted mean of (M = 114.05), whereas the 5E instructional model group had a higher mean self-efficacy rating of (M = 116.03, SD = 5.42) with an adjusted mean of (M = 116.02). The difference in their adjusted mean self-efficacy ratings shows that the group taught with the 5E instructional model had higher adjusted mean than the group taught with the cognitive conflict model. However, the posttest standard deviations of 4.25 and 5.42 for the students exposed to cognitive conflict instructional and 5E instructional models respectively, imply that the individual self-efficacy ratings of the cognitive conflict instructional model group were closer to the mean than those of the students exposed to 5E instructional model. Hypothesis 2: There is a significant difference in the mean self-efficacy ratings of students taught particulate nature of matter using cognitive conflict instructional model and those taught using the 5E instructional model. Table 4 shows the test of the homogeneity of variances of the two groups. The analysis indicates that the variances are equal across the two groups, F(1, 193) = 0.323, p = .571. This is for the fact that the pvalue of .571 is larger than the .05 level of significance. Table 4 indicates that there is a significant effect of the instructional model on students' self-efficacy in particulate nature of matter, F(1, 192) = 8.259, p = .005. This means that there is a significant difference in the mean self-efficacy ratings of students taught particulate nature of matter using the cognitive conflict instructional model and those taught using the 5E instructional model in favor of those taught using 5E instructional model. Besides, the effect size of 0.041 means that a 4.1% variation in the self-efficacy ratings of the students is as a result of their exposure to the 5E instructional model. This confirms that the 5E instructional model enhances students' self-efficacy more than the cognitive conflict instructional model.

Discussion of the Findings
This study sought the instructional efficacies of cognitive conflict and 5E instructional models on students' conceptual change achievement and self-efficacy in particulate nature of matter concepts in physics. Students taught particulate nature of matter using the cognitive conflict instructional model and those taught using the 5E instructional model had significant differences in mean conceptual change achievement scores and mean self-efficacy ratings, with those taught using the 5E instructional model outperforming those taught using the cognitive conflict instructional model. This suggests that the 5E teaching approach enhances students' conceptual change achievement scores and self-efficacy more than the cognitive conflict instructional model, as evaluated by the difference in their mean self-efficacy rating. This shows that the 5E teaching paradigm has a greater impact on students' conceptual change achievement and self-efficacy than the cognitive conflict model. The superiority of the 5E instructional model over the cognitive conflict instructional model in enhancing students' conceptual change achievement and self-efficacy in particulate nature of matter could be attributed to the fact that the evaluation stage in the instructional model is placed at the center stage as the lesson progresses. Students can   Okafor's (2016) findings that the 5E learning cycle model improved students' geometry achievement and retention. According to Umahaba (2018), the 5E teaching paradigm improved students' ability to tackle increasingly difficult problems in chemistry performance evaluations. Orji (2013) supports this conclusion, finding cognitive conflict to be beneficial in developing students' conceptual change. The study found a link between the cognitive conflict approach and conceptual change pedagogy, but not with the 5E teaching paradigm. According to Labobar et al. (2017), students' misinterpretation of concepts was significant before therapy utilizing the cognitive conflict technique, but it was reduced after treatment. Cognitive conflict tactics influenced students' conceptual transformations, according to the findings. According to Wartono et al. (2018), cognitive conflict strategies may be utilized to eliminate misconceptions and improve students' learning accomplishment, confirming Labobar et al. (2017) findings. According to Saputro et al. (2020), Vishnumolakala et al. (2018), Kandil and Is xıksal-Bostan (2019), cognitive conflict and 5E instructional approaches greatly increased students' self-efficacy. The constructivist model problem-based learning-predict observe explain (PBLPOE), which is related to the 5Es teaching technique, greatly boosted students' self-efficacy, according to Fitriani et al. (2020). This finding is consistent with earlier studies that show that using either the cognitive conflict teaching model or the 5E instructional model enhanced students' performance (Opara & Waswa, 2013;Tuna & Kacar, 2013;Utari et al., 2013).

Limitations of the Findings
Obviously, this study faces obstacles that restrict the generalizability of its conclusions. One of these issues is the use of different teachers to teach the topics, despite the fact that they had been trained prior to the study's implementation. It is not safe to presume that their cognitive and affective factors are same. As a result, the study's findings may be influenced. The learners in this study's age and social background differences may potentially represent a difficulty in terms of concept creation and information processing when it comes to learning including conceptual transformation. The generality of the result may be harmed by the inherent limitation of the quasi-experimental study, which does not allow for subject randomization. Although ANCOVA assisted in the homogenization of the groups, it was unable to eradicate the discrepancies. Again, using cognitive conflict and 5E instructional approaches to teach for conceptual change takes time. The 1-hr provided for each session had such an impact on the school schedule that many teachers complained that the lesson had encroached on their own time. As a result, in the majority of cases, the time issue corrupted the lessons.

Conclusion and Recommendations
The impact of cognitive conflict and 5E teaching styles on students' conceptual change achievement and selfefficacy in physics was investigated in this study. In particulate nature of matter, students who were exposed to the 5E and cognitive conflict instructional models outperformed their pretest in terms of post-conceptual change achievement and post-self-efficacy ratings. The models have been shown to help people improve their self-efficacy in general. In particulate nature of matter in physics, the 5E teaching style appeared to be more effective than cognitive conflict in developing students' conceptual change achievement and self-efficacy. This could be because students in the 5E instructional group engage and interact with one another and with the environment in a more exploratory manner than students in the cognitive conflict group.
These encounters with the environment have a tendency to alter their self-efficacy belief and conceptual change achievement. This may influence students' instructional activities, goal setting, and preparation to continue and accomplish difficult assignments. As a result, using the 5E instructional model improves students' conceptual change achievement and self-efficacy more than using the cognitive conflict instructional model. To put it another way, implementing the 5E instructional model will improve students' conceptual change achievement and physics self-efficacy. As a result, we advocate that: Students show their knowledge of atom by saying that atom is one of the following building unit, matter, or compounds.

Presentation of anomalous situation
The teacher asks the students to open perfume bottle provided in order to investigate how the particle of gas move. He asks the students to state their observations.
Students perform the activity to investigate how particle of a gas move. Students record their observations. Students think freely within the time and interact within themselves as they record their observations. They explain that atom is made up of proton, neutron, and electron. Creation of cognitive conflict The activity of opening the perfume bottle and observation will create a conflict with the already conceptions as held by the students.
The students are set into cognitive conflicts by this activity. They began to question their findings from the activities and this will lead them into the next step.

Students' interaction with peers
Teacher encourages students to explain concepts in their own words and asks for justification of their explanation. He asks the students to place a 1 g sample of solid iodine a glass tube and allow it for a long time on heating until all the iodine evaporates and the tube is filled with iodine gas. The teacher further explains that diffusion also takes place in liquids but much slower than in gases. This is because the particles of a liquid move much more slowly Students observe that all gas diffuse to fill the space available. Gases diffuse at different rates. They listen to explanation of others. They question other's explanations, listen and try to comprehend explanations-given by the teacher and refers to previous activities to assess their own understanding and reconstruct knowledge based on the scientific evidence as observed in the activities. The teacher assesses the level of students' change from naïve conception to sound conception by asking the following questions: What is matter? What are the constituent of an atom?
Students attempt the given questions. Atom simply consists of electron and nucleus made up of proton and neutron held together by electric forces. The nucleus as the heavy portion of the atom is located at its center. Summary The teacher summaries the main point for the evidence of particle nature of matter.
Students note the points to consolidate their understanding. Assignment Consider the following statements and sort them into true or false. v. In a solid the particles are not moving. vi. The particles in a gas are very far apart. vii. In a liquid the particles are constantly jumping into each other. viii. The particles in a gas are moving at high speed.
Students classify the statements into true or false according to their current knowledge.

Content: Molecules
Steps Teacher's activity Students' activity Identifying students' current state of knowledge The teacher creates interest by asking them to draw a football using dots possibly with different ink. How does football move in air? Using toothpicks, and four colors of candy, have the students make a model of these molecules: NaCl-table salt O 2 -oxygen H 2 O-water The teacher asks students to describe the basic difference in elements, molecules, and compounds. Fill a tray with clean water and when the surface is still, sprinkle talcum powder lightly on it thereafter a drop of olive oil and compare it with the first activity. Measure the diameter of oil film formed.
The students draw the football and respond how it moves in zig zag manner.
A major misconception is that many students think that molecules are in substances rather than that they make up substances. The students engage in the experiment to determine the molecular size. They record their observations. The students were encouraged to explain their observations with the relationship as: Area of film = pR 2 Where R is the radius of the film and r is the radius of the drop. Volume of film = pR 2 h Where h is the thickness of the film. Volume of spherical drop = 4 = 3 pr 3 But volume of film = volume of drop )pR 2 h = 4 = 3 pr 3 Presentation of anomalous situation The teacher encourages the students to work in groups. He guides the students by providing leading questions such as: what will the thickness of the film called? What could be the size? The teacher informs the students that instead of measuring the size of the drop to obtain its volume, a pipette of known volume can be used and a drop can be run from the pipette to the surface of the water. In this case: The students think freely and discover the size of the molecule as sampled. Thickness of film = length of molecule = 4 = 3 pr 3 /pR 2 4 = 3 r 3 /R 2 The students ask question where they are challenged to arrive at the size of the molecule. They arrived at a range of values of the order of 10 27 m. Students attempt to measure size of molecule using pipette.

Creation of cognitive conflict
Guide students to investigate. This will create a conflict with the already conceptions as held by the students.
The students are set into cognitive conflicts. They began to question their findings from the activities and this will lead them into the next step.

Students' interaction with peers
The teacher asks the students to: burn a straw and equally observe the smoke trapped in a small glass cell under the microscope. The teacher leads students as they interact among themselves and provide clarification for students to understand the concepts.
The students observe the Brownian motion of the particles of smoke and discover that molecules of a substance move relative to other molecules of the same substance. They observed that the size of molecules is very small. Brownian motion is an evidence for the existence of molecules which are too small to be observed directly. Secondly, it is evidence that molecules are not still but are in continual motion. Students discover that actual size of molecules is trillion times smaller than the dots or spheres we use to represent them. The teacher leads discussions that will further improve students' thinking. When two inverted jar of gas is separated by a glass. What do you observe? If the glass is carefully removed? The teacher uses probing questions to lead students' thinking. The teacher refers students to existing data and evidence and asks students what do they know? The teacher leads the students to remember that both gases consist of molecules in continual rapid motion. The teacher guides the students through probing questions to discover that the rate of diffusion depends on densities of the gases as well as the temperature.
The students observed the two gas jars. One full of hydrogen, a light gas and the other full of carbon dioxide a heavy gas and are separated by a glass cover. The students observed that when the glass cover is carefully removed after a while both gas jars contain a mixture of carbon dioxide and hydrogen through a chemical test. The students experience disequilibrium that the heavier carbon dioxide is able to move upward against gravity and the lighter hydrogen moves downward to give a uniform mixture. Students expected the heavier gas to stay at the bottom and the lighter gas at the top. The students discover that the tendency of a gas to fill an empty space as a result of the constant random motion of the molecules is called diffusion. Evaluation of students' degree of conceptual change The teacher use the following questions to access the students' understanding. How would you estimate the size of a molecule of oil? What do you understand by Brownian motion? State two characteristics of a molecule?
Students attempt the questions from the teacher.

Summary
Based on students' answers, the teacher does the corrections while emphasizing the main points.
Students took note of the correct answers and share ideas with each other, assessing their level of understanding based on their scores. Assignment (1) Work out the following into molecule or compound and write the rule you can follow to determine the difference. (2) Draw the structure of sodium chloride crystal. The students observe the structure of sodium chloride crystal provided. The students through the activities experience disequilibrium and ask question for clarity. The students individually. Observe heating of crystalline substance such as sugar sodium chloride.

Presentation of anomalous situation
The teacher asks them to give the names of what make up crystals confirming the particle's in crystal guide the students to discover that there is no free motion in crystals. Leads them to discover that the arrangement of molecules in crystal is referred to as crystalline lattice.
The students think freely, discussing their ideas with others to form prediction and come up with the idea that crystals are made up of atoms, ions, or molecules that are arranged in a regular repeating pattern. The students through guided questions describe the structure of the crystal. In crystals, the atoms, molecules, or ions are usually arranged in orderly regular manner because of the force binding them. The force of cohesion holding the molecules in solids is greater than those holding in liquid.

Creation of cognitive conflict
Guides students to investigate. This will create a conflict with the already conceptions as held by the students.
The students are set into cognitive conflicts. They began to question their findings from the activities and this will lead them into the next step.

Students' interaction with peers
The teacher confirms the students understanding and led them to discover that crystal lattices are usually measured by X-rays. The teacher confirms the students understanding on the characteristics of crystal and led them through explanation that other crystal are composed of molecules and are named molecular. Crystals for example solid carbon dioxide, while crystals with atoms in their lattice are called atomic crystals. The teacher observe them as they compare crystalline and non-crystalline substances The students through activities they have explored discovered that different lattices produce different shapes of crystals peculiar to that compound. Substance of the same crystalline shape are referred to as isomophous. They discover that the melting points of crystalline substances are usually high because a lot of energy is needed to break the strong force binding the ions together from their observation they discover that sodium crystals consist atoms held together by shared electrons like diamond graphite and quartz. Students through interaction with peers compare amorphous and crystalline substances. They discover that amorphous substances have no definite shapes and no definite melting points. They do not have the regular arrangement of atoms as such they are more of than solids. Discussion/ summary The teacher asks them to recall examples of crystalline and amorphous substances giving correction where necessary. The teacher leads them to draw the heating and cooling curves for crystalline and non crystalline substances.
One after the other they mention that amorphous substances include glass, plastics, wood and they do not form crystals but have long chain-like molecules that are interwined in the liquid state. They give the heating and cooling curve for crystalline and amorphous substances as sampled below. Evaluation of students' degree of conceptual change The teacher uses the following questions to evaluate the students distinguish between crystalline and amorphous substances. What is a crystal? Mention three characteristics of crystalline.
The students attempt the questions asking questions where they are confused and noting down the teacher's correction.

Summary
The teacher summaries the main points, states types and characteristics of crystals, and gives necessary corrections.
Students note the different between crystalline and amorphous substances.

Assignment
Draw the sodium chloride crystal The students draw the crystal structure of sodium chloride on their exercise book. The teacher asks the students to classify materials into solid, liquid, or gas and recall the concept of energy with reference to kinetic energy. What processes are involved in changing states? This is to enable the teacher identify the students' naïve conceptions. The teacher ensures that students gave reasons for their answer.
Students recall Brownian motion to make connection with the previous knowledge and present learning. Students name melting, boiling, evaporation, and freezing. These show their naïve conceptions

Presentation of anomalous situation
We will use the kinetic particle theory to visualize how matter exists in three states: solid, liquid, and gas with distinction on the arrangement of atoms, molecules, and particles in matter as well as their relative motion. Guide students to investigate that in solids, the kinetic energy is low and have strong attractive forces. In liquids, kinetic energy and attractive forces are higher than solids and lower than gases. In gas, the kinetic energy is high and weak attractive forces.
Students visualize the model to illustrate the three states of matter. Using a sample of liquid ammonia (NH 3 ) is completely evaporated in a close container as shown.
They think freely and form new prediction from their alternative conception and discuss them with peers. They suspended judgment and try to understand terms involving states of matter.

Creation of cognitive conflict
Guides students to investigate the three states of matter. This will create a conflict with the already conceptions held by the students. The students will then set to discover new information.
The students began to question their findings from the activities. In solids, the kinetic energy is low and has strong attractive forces. In liquids, kinetic energy and attractive forces are higher than solids and lower than gases. In gas, the kinetic energy is high and weak attractive forces.

Students' interaction with peers
Invites students to explain their observations and give reasons for possible solutions. Formally clarifies definitions to correct students' naïve conceptions. Use model to illustrate the three states of matter and explain thus. A solid, at a given temperature has a definite volume and shape. In solids, particles attract one another and they are arranged in a regular manner as such, many solids form crystals. A liquid at any given temperature has a fixed volume and will take up the shape of any container into which it is poured. The particles are close together but they can move around way and often collide. The teacher invites the students to develop more understanding by elaborating that kinetic theory is the theory which takes this simple fact that molecules are continually moving and uses this to explain the behavior of matter. Hence molecules will bend or vibrate but will stay in close proximity.
Ask questions to get further clarification. To understand better, they try an activity where they hold a plastic bottle filled with water and covered and try to squeeze it but find it difficult to, unlike when it is gas. Students will also understand that particles of a liquid are attracted much more than they are almost as close together as a solid but they can slide past each other. They are so close together that they cannot be squeezed. Evaluation of students' degree of conceptual change The teacher assesses students' understanding if it corresponds to the kinetic molecular theory with matter is composed of tiny particles (molecules). The measure of space that the molecules occupy (volume) is derived from the space in between the molecules and not the space the molecules contain themselves.
Students answer questions that probe their scientific understanding of concepts based on the molecular theory. Students respond to the questions to show their knowledge of the concept.

Summary
The teacher summaries the main points and gives necessary correction.
Students note the correction given by the teacher.

Assignment
Explain the three states of matter using molecular theory of matter.
Students explain the three states of matter using the molecular theory of matter in the note books.

Content: Photon
Steps Students are motivated and question to uncover what they already know about light. Light is a sources of energy and we use sun light to dry our clothes. Students perform the activities and record their observation.

Presentation of anomalous situation
From the quantum theory Bohr proposed that electron in the atom exist in discrete energy state (quantized) is this what you see? Teacher encourages students to work together and the teacher keep asking probing questions to redirect students' investigation Students enter into activity to observe the energy levels in an atom. Students test prediction and record observations and ideas. Ask related questions. The students were able to state that the in photoelectric phenomena, the transfer of energy between light and electron take place between packets of light energy and the electron. Therefore, there is instantaneous emission at very low temperature.

Creation of cognitive conflict
Guide students to investigate. This will create a conflict with the already conceptions as held by the students.
The students are set into cognitive conflicts. They began to question their findings from the activities and this will lead them into the next step.

Students' interaction with peers
Asks student to justify their explanations. To explain the radiation curves from a black body, electrons have distinct values of energy. Electron wage its energy in well defined steps given by En = nhf If an atom absorbs energy and transits to another energy level, such atom is said to be in an excited state. The teacher explains that light is considered as packets of energy which is compared to particles and this is called photons. Given as E = hf = hc \ Solution En -Eo = 6.7 eV En -(210.4) = 6.7 eV : En = 23.7 eV But this is the energy of the third level. E2 -E1 = 23.7 -(25.5) = 1.8 eV For the wavelength of the emitted atom, recall the energy lost by an atom in Is equal to the energy of the emitted photon. That is, 1.8 eV = hĉ = 6:6 x 10 À34 x 3 10 8 1:8 x 1:6 x 10À19 = 6.9 3 10 27 m Discussion/ summary Reminds the students to know that a photon is a changeless particle whose spin is I and Has zero rest mass. It is a stable particle with on infinite lifetime.
The teacher elaborates further that we use the concept of photon to explain that light behave like particles show spectra for different atoms. Solids, liquids, and gases under high pressure produce continuous spectra which gives a characteristic nature of the substance.
Students apply new definitions and checks for peers. Discover that the study of spectra is known as spectroscopy and that optical emission spectra are three types which include; continuous, band, and line spectra. Students classify spectra into two: emission and absorption spectra. Photons have some basic properties that help define what they are and how they behave. These properties include: They have zero mass. They have no electric charge. They are stable. They carry energy and momentum which are dependent on the frequency. They can have interactions with other particles such as electrons. They can be destroyed or created by many natural processes. When in empty space, they travel at the speed of light.

(continued)
Appendix B

First Lesson Plan With 5E Instructional Model
Subject: Physics Topic: Particulate nature of matter Unit: Structure of matter Class: SS1 Duration: 80 min Instructional Objectives: By the end of the lesson students should be able to: 1. Explain the meaning of atom 2. Describe the atomic structure 3. State the constituents of the atom 4. Formulate simple hypothesis and test them before they can draw conclusion on specific information on the evidence of particle nature of matter.
Instructional Materials: Perfume bottle, air fresher bottle, 1 g of solid iodine, glass tube, cube of sugar, and water. Entry Behavior: Students have preconceptions on the concepts of particle atom and matter.
Test of Entry Behavior: The teacher uses the following to determine the students' preconception. What is the difference between air and oxygen? Is all matter visible? What do you know about matter? What is the difference between particle and matter? Differentiation of Strategies: Teacher sets different activities to meet diverse learner needs. (continued)

Content: Photon
Steps Teacher's activity Students' activity Evaluation of students' degree of conceptual change The teacher evaluates the level of students' conceptual change by asking them to mention the three ways in which atom can absorb energy.
Students give possible answers to demonstrate their understanding atoms can absorb energy through. i. In a flame as in elastic collisions with molecules. ii. In a discharge tube as in elastic collisions with bombarding electrons. iii. From a photon. Summary The teacher summaries the main point and gives correction where necessary to consolidate students' understanding.
Students copy the correction and ask questions for more learning.

Assignment
Explain three ways atom can absorb energy Students attempt the question and show their note books.

Content: Structure of matter
Steps Teacher's activity Students' activity

Engagement
The teacher writes the word ATOM on the board and asks the students to state what they know about it?
Students show their knowledge of atom by saying that atom is one of the following building unit, matter, small substance, molecules, elements, a particle, or compounds. Exploration The teacher asks the students to open perfume bottle provided and state their observation. This is to allow the students to explore with the new materials. He uses probing questions to guide students' investigation on how the particles of gas move. He asks the students to state their observations.
Students perform the activity to investigate how particle of a gas move. Students record their observations. Students think freely within the time and interact within themselves as they record their observation. They explain that atom is made up of proton, neutron and electron evidence a model to explain the atom. The teacher asks the students to place a 1 g sample of solid iodine a glass tube and allow it for a long time on heating until all the iodine evaporates and the tube is filled with iodine gas. Teacher encourages students to explain concepts in their own words and asks for justification of their explanation. The teacher further explains that diffusion also takes palace in liquids but much slower than in gases. This is because the particles of a liquid move much more slowly Students observe that all gas diffuse to fill the space available. Gases diffuse at different rates. They listen to explanation of others. They question other's explanations, listen and try to comprehend explanationsgiven by the teacher and refers to previous activities to assess their own understanding and reconstruct knowledge based on the scientific evidence as observed in the activities. Elaboration The teacher describes the Brownian motion to further elaborate the concept for students' understanding of the concepts. Brownian motion as the motion of visible particles (pollen grains) caused by much smaller, invisible ones (water particles). This explains the kinetic particle model of matter which assumes that matter is made up of tiny constantly moving particles called atoms. Different substances have different types of particles (atom, molecules, or ions). Heavier particles move more slowly than lighter ones at a given temperatures Students correct previous understanding with the new situation and systematically change their conception about atom and its constituents.
Fig3 pollen grains particle being bombarded by water molecules. Students ask questions, make decisions and design experiment to draw reasonable conclusions from evidence. Evaluation The teacher evaluates the level of students' change from naïve conception to sound conception by asking the following questions: What is matter? What are the constituent of an atom?
Students attempt the given questions. Atom simply consists of electron and nucleus made up of proton and neutron held together by electric forces. The nucleus as the heavy portion of the atom is located at its center. Summary The teacher summaries the main point for the evidence of particle nature of matter.
Students note the points to consolidate their understanding Assignment Consider the following statements and sort them into true or false. v. In a solid the particles are not moving. vi. The particles in a gas are very far apart. vii. In a liquid the particles are constantly jumping into each other. viii. The particles in a gas are moving at high speed.
Students classify the statements into true or false according to their current knowledge. The students draw the football and respond how it moves in zig zag manner.

Second Lesson Plan With 5E Instructional Model
A major misconception is that many students think that molecules are in substances rather than that they make up substances. The students engage in the experiment to determine the molecular size. They record their observations. The students were encouraged to explain their observations with the relationship as: Area of film = pR 2 Where R is the radius of the film and r is the radius of the drop. Volume of film = pR 2 h Where h is the thickness of the film. Volume of spherical drop = 4 = 3 pr 3 But volume of film = volume of drop )pR 2 h = 4 = 3 pr 3 Exploration The teacher encourages the students to work in groups.
He guides the students by providing leading questions such as: what will the thickness of the film called? What could be the size? The teacher informs the students that instead of measuring the size of the drop to obtain its volume, a pipette of known volume can be used and a drop is run from the pipette to the surface of the water. In this case: The students think freely and discover the size of the molecule as sampled. Thickness of film = length of molecule = 4 = 3 pr 3 /pR 2 4 = 3 r 3 /R 2 The students ask question where they are challenged to arrive at the size of the molecule. They arrived at a range of values of the order of 10 27 m. Students attempt to measure size of molecule using pipette. (continued)

Content: Molecules
Steps Teacher's activity Students' activity Explanation The teacher asks the students to burn a straw and observes the smoke form trapped in a small glass cell under the microscope. The teacher leads discussion and provides clarification for students. Brownian motion is an evidence for the existence of molecules which are too small to be observed directly. Secondly, it is evidence that molecules are not still but are in continual motion.
The students observe the Brownian motion of the particles of smoke and discover that molecules of a substance move relative to other molecules of the same substance. They observed that the size of molecules is very small. Students discover that actual size of molecules is trillion times smaller than the dots or spheres we use to represent them.

Elaboration
The teacher provides an activity that will further elaborate students' thinking. When two inverted jar of gas is separated by a glass. What do you observe? If the glass is carefully removed? The teacher uses probing questions to lead students' thinking. The teacher refers students to existing data and evidence and asks students what do they know? The teacher leads the students to remember that both gases consist of molecules in continual rapid motion. The teacher guides the students through probing questions to discover that the rate of diffusion depends on densities of the gases as well as the temperature.
The students observed the two gas jars. One full of hydrogen, a light gas and the other full of carbon dioxide a heavy gas and are separated by a glass cover. The students observed that when the glass cover is carefully removed after a while both gas jars contain a mixture of carbon dioxide and hydrogen through a chemical test. The students experience disequilibrium that the heavier carbon dioxide is able to move upward against gravity and the lighter hydrogen moves downward to give a uniform mixture. Students expected the heavier gas to stay at the bottom and the lighter gas at the top. The students discover that the tendency of a gas to fill an empty space as a result of the constant random motion of the molecules is called diffusion. Evaluation The teacher uses the following questions to access the students' understanding. How would you estimate the size of a molecule of oil? What do you understand by Brownian motion? State two characteristics of a molecule?
Students attempt the questions given by the teacher.

Summary
Based on students' answers, the teacher does the corrections while emphasizing the main points.
Students took note of the correct answers and share ideas with each other, assessing their level of understanding based on their scores.

Assignment
(1) Work out the following into molecule or compound and write the rule you can follow to determine the difference.
(2) Draw the structure of sodium chloride crystal. The students observe the structure of the sodium chloride crystal provided. The students through the activities experience disequilibrium and ask question for clarity. Observe heating of crystalline substance such as sugar, sodium chloride.

Exploration
The teacher asks them to give the names of what make up crystals confirming the particle's in crystal guide the students to discover that there is no free motion in crystals. Leads them to discover that the arrangement of molecules in crystal is referred to as crystalline lattice.
The students think freely, discussing their ideas with others to form prediction and come up with the idea that crystals are made up of atoms, ions, or molecules that are arranged in a regular repeating pattern. The students through guided questions describe the structure of the crystal. In crystals, the atoms, molecules, or ions are usually arranged in orderly regular manner because of the force binding them. The force of cohesion holding the molecules in solids is greater than those holding in liquid.

Explanation
The teacher confirms the students understanding and leads them to discover that crystal lattices are usually measured by X-rays. The teacher confirms the students understanding on the characteristics of crystal and led them through explanation that other crystal are composed of molecules and are named molecular. Crystals for example solid carbon dioxide, while crystals with atoms in their lattice are called atomic crystals. The teacher observe them as they compare crystalline and non-crystalline substances The students through activities they have explored discovered that different lattices produce different shapes of crystals peculiar to that compound. Substance of the same crystalline shape are referred to as isomophous. They discover that the melting points of crystalline substances are usually high because a lot of energy is needed to break the strong force binding the ions together from their observation they discover that sodium crystals consist atoms held together by shared electrons like diamond graphite and quartz. Students through interaction with peers compare amorphous and crystalline substances. They discover that amorphous substances have no definite shapes and no definite melting points. They do not have the regular arrangement of atoms as such they are more of than solids. One after the other they mention that amorphous substances include glass, plastics, wood and they do not form crystals but have long chain-like molecules that are interwined in the liquid state. They give the heating and cooling curve for crystalline and amorphous substances as sampled below. Evaluation The teacher uses the following questions to evaluate the students: Distinguish between crystalline and amorphous substances. What is a crystal? Mention three characteristics of crystalline The students attempt the questions and noting down the teacher's correction.

Summary
The teacher summaries the main points, states types and characteristics of crystals, and gives necessary corrections.
Students note the different between crystalline and amorphous substances.

Assignment
Draw the sodium chloride crystal The students draw the crystal structure of sodium chloride on their exercise book.

Content: States of matter
Steps Teacher's activity Students' activity

Engagement
The teacher asks the students to classify materials into solid, liquid or gas and recall the concept of energy with reference to kinetic energy. What processes are involved in changing states?
Students recall Brownian motion to make connection with the previous knowledge and present learning. Students name melting, boiling, evaporation, and freezing. Teacher's activity Students' activity Exploration We will use the kinetic particle theory to visualize how matter exists in three states: solid, liquid, and gas with distinction on the arrangement of atoms, molecules, and particles in matter as well as their relative motion. Guide students to investigate that in solids, the kinetic energy is low and have strong attractive forces. In liquids, kinetic energy and attractive forces are higher than solids and lower than gases. In gas, the kinetic energy is high and weak attractive forces.
Students visualize the model to illustrate the three states of matter. Using a sample of liquid ammonia (NH 3 ) is completely evaporated in a close container as shown.
They think freely and form new prediction from their alternative conception and discuss them with peers. They suspended judgment and try to understand terms involving states of matter. Explanation Invites students to explain their observations and give reasons for possible solutions. Formally clarifies definitions to correct students' naïve conceptions. Use model to illustrate the three states of matter and explain thus. A solid, at a given temperature has a definite volume and shape. In solids, particles attract one another and they are arranged in a regular manner as such, many solids form crystals. A liquid at any given temperature has a fixed volume and will take up the shape of any container into which it is poured. The particles are close together but they can move around way and often collide. The force of attraction between particles are Give different explanations involving phase change of matter. When water boils, it molecules escae and forms air. When solids melts, it particles flow away just like the case of candle wax and ice.

Elaboration
The teacher invites the students to develops more understanding by elaborating that kinetic theory is the theory which takes this simple fact that molecules are continually moving and uses this to explain the behavior of matter. Hence molecules will bend or vibrate but will stay in close proximity.
Ask questions to get further clarification. To understand better, they try an activity where they hold a plastic bottle filled with water and covered and try to squeeze it but find it difficult to, unlike when it is gas. Students will also understand that particles of a liquid are attracted much more than they are almost as close together as a solid but they can slide past each other. They are so close together that they cannot be squeezed. Evaluation The teacher assess students' understanding if it corresponds to the kinetic molecular theory with matter is composed of tiny particles (molecules). The measure of space that the molecules occupy (volume) is derived from the space in between the molecules and not the space the molecules contain themselves.
Students answer questions that probe their scientific understanding of concepts based on the molecular theory. Students respond to the questions to show their understanding of the concept.

Summary
The teacher summaries the main points and gives necessary correction.
Students note the correction given by the teacher.

Assignment
Explain the three states of matter using molecular theory of matter Students explain the three states of matter using the molecular theory of matter in the note books.

Fifth Lesson Plan With 5E Instructional Model
Subject: Physics Topic: Particulate nature of matter Unit: Photon Class: SS1 Duration: 80 min Instructional Objectives: By the end of the lesson students should be able to: 1. Explain the meaning of photon 2. State the particle properties of a photon 3. Use the concept of photon to explain that light behaves like particle 4. State three ways atom can absorb energy Instructional Materials: Black box Entry Behavior: Students preconceptions of particle and matter Test of Entry Behavior: The teacher uses the following questions to determine the students' preconception. Where does light comes from? Differentiation of Strategies: teacher set different activities to meet diverse learner needs.

Content: Photon
Steps Teacher's activity Students' activity

Engagement
The teacher asks question to generate interest and create curiosity. Light is composed of what? Shine a touch into the black box and what do you observe? The teacher presents the Photon model of light.
Students are motivated and question to uncover what they already know about light. Light is a sources of energy and we use sun light to dry our clothes. Students perform the activities and record their observation.

Exploration
From the quantum theory Bohr proposed that electron in the atom exist in discrete energy state (quantized) is this what you see? Teacher encourages students to work together and the teacher keep asking probing questions to redirect students' investigation Students enter into activity to observe the energy levels in an atom. Students test prediction and record observations and ideas. Ask related questions. The students were able to state that the in photoelectric phenomena, the transfer of energy between light and electron take place between packets of light energy and the electron. Therefore, there is instantaneous emission at very low temperature. Explanation Ask student to justify their explanations. To explain the radiation curves from a black body, electrons have distinct values of energy. Electron wage its energy in well defined steps given by En = nhf If an atom absorbs energy and transits to another energy level, such atom is said to be in an excited state. The teacher explains that light is considered as packets of energy which is compared to particles and this is called photons. Given as E = hf = hc \ Solution En -Eo = 6.7 eV En -(210.4) = 6.7 eV :. En = 23.7 eV But this is the energy of the third level. E2 -E1 = 23.7 -(25.5) = 1.8 eV For the wavelength of the emitted atom, recall the energy lost by the atom Is equal to the energy of the emitted photon. That is, 1.8 eV = hĉ = 6:6 x 10 À34 x 3 10 8 1:8 x 1:6 x 10À19 = 6.9 3 10 27 m (continued)

Content: Photon
Steps Teacher's activity Students' activity

Elaboration
Remind the students to know that a photon is a changeless particle whose spin is I and Has zero rest mass. It is a stable particle with on infinite lifetime.
The teacher elaborates further that we use the concept photon to explain that light behave like particles show spectra for different atoms. Solids, liquids, and gases under high pressure produce continuous spectra which gives a characteristic nature of the substance.
Students apply new definitions and checks for peers. Discover that the study of spectra is known as spectroscopy and that optical emission spectra are three types namely continuous, band, and line spectra. Students classify spectra into two: emission and absorption spectra. Photons have some basic properties that help define what they are and how they behave. These properties include: They have zero mass. They have no electric charge. They are stable. They carry energy and momentum which are dependent on the frequency. They can have interactions with other particles such as electrons. They can be destroyed or created by many natural processes. When in empty space, they travel at the speed of light. Evaluation The teacher evaluates students' level of conceptual change from naïve to sound conception by asking them to mention the three ways in which atom can absorb energy.
Students give possible answers to demonstrate their understanding atoms can absorb energy through. i. In a flame as in elastic collisions with molecules. ii. In a discharge tube as in elastic collisions with bombarding electrons iii. From a photon. Summary The teacher summaries the main point and gives correction where necessary to consolidate students' understanding.
Students copy the correction and ask questions for more learning.

Assignment
Explain three ways atom can absorb energy Students attempt the question and show their note books.