FIRST YEAR UNIVERSITY STUDENTS’ CONCEPTUAL UNDERSTANDING OF PHYSICAL AND CHEMICAL CHANGES (A Preliminary Research)

The purpose of this study is to identify first year university students' understanding of the concepts of physical and chemical changes. This study involved 43 students from the 2019 batch of the Chemical Education Study Program (PSPK) of the Faculty of Science and Education (FKIP) of the Syiah Kuala University (USK) which was dominated by women (only 2 men). According to the objectives, the study used a survey method and used an instrument in the form of a questionnaire containing 15 statements. Participants were asked to provide responses via google form by choosing true or false for each statement item on the questionnaire. The results of the analysis show that the understanding of the majority of students is quite good for macroscopic markers or indicators and low for sub-microscopic markers or indicators. Therefore, chemistry teachers need to use molecular (sub-microscopic) images when teaching materials or topics of physical and chemical changes.

THE EFFECTIVENESS OF WORKSHEET-ASSISTED PROBING PROMPTING LEARNING MODEL ON STUDENTS’ CRITICAL THINKING SKILLS IN THE SUBJECT OF REACTION RATE AT MAS ULUMUDDIN LHOKSEUMAWE

This study aimed to determine the differences in critical thinking skills (CTS) between classes using the worksheet-assisted probing prompting learning model and those using only probing prompting learning model for the subject of reaction rate at MAS Ulumuddin Lhokseumawe. The research method was quasi-experimental with the Nonequivalent Control Group research design. The sample used were two classes with 30 students in each. The data was collected by using multiple choice test questions. The results showed that there were differences in the critical thinking skills of students who were taught using the worksheet-assisted probing prompting learning model and students who were taught with only probing prompting learning model. Since there was a significant value of 0.000 0.05, then the Ha was accepted while the H0 was rejected. It can be concluded that there is a significant effect of the probing prompting learning model assisted with students’ worksheet on the critical thinking skills of students at MAS Ulumuddin Lhokseumawe.

DEVELOPMENT OF INTERTEXTUAL BASED LEARNING STRATEGY USING VISUALIZATION MODEL TO IMPROVE SPATIAL ABILITY ON MOLECULAR GEOMETRY CONCEPT

This study aims to develop intertextual-based learning strategies using visualization models to improve students' spatial abilities on molecular geometry concepts. In this study using the method of Research and Development (RD). The research subjects used were 20 high school 10th grade students. In this study the instrument used was in the form of an intertextual-based learning strategy validation sheet with visualization models, 3D visualization software, and spatial ability tests. Spatial ability consists of three indicators to be evaluated, namely spatial relations, spatial orientation, and spatial visualization. The results of intertextual-based learning strategy research with developed visualization models can improve spatial ability. Students can understand molecular geometry from the concept of VSEPR theory and valence bond theory. Results pre-test student on the spatial relations (26.67%), spatial orientation (10.10%), and spatial visualization (7.41%). After being tested intertextual-based learning strategies with visualization models of students' post-test results on the spatial relations (58.33%), spatial orientation (50.00%), and spatial visualization (27.78%).

THE EFFECT OF PROCESS ORIENTED GUIDED INQUIRY LEARNING (POGIL) MODEL ON SCIENCE PROCESS SKILLS (SPS) AND STUDENTS' COGNITIVE ABILITIES ON THE CONCEPT OF REACTION RATE

This study aims to determine the effect of the Process Oriented Guided Inquiry Learning (POGIL) model on Science Process Skills (SPS), cognitive abilities and the correlation between SPS and students' cognitive abilities on the reaction rate concept. The sample in this study were 35 students of class XI SMA Negeri Seribu Bukit 2016/2017 academic year. The data was collected through observation and test. 20 multiple choice questions (alpha=0.81) were used to collect data of student’s SPS. While students' cognitive abilities were obtained by pre-test and post-test using 20 multiple choice questions (alpha=0.84). The distributed normally and homogeneously. The hypothesis was tested by using Paired Sample t-Test at a significance level of 0.05. Based on the data analysis and hypothesis testing carried out, there was a significant difference in the effect of the POGIL model on Science Process Skills (SPS), cognitive abilities and significant interactions between SPS and students' cognitive abilities on the material reaction rate, indicated by the value of each probability or sig. 0,000 0.05, so it can be concluded that the results of testing the hypothesis reject Ho or accept Ha at the 5% alpha level.

IMPLEMENTATION OF 2 STAY 2 STRAY MODEL IN LEARNING THE CONCEPT OF α, β, AND γ RADIATIONS

The two stay two stray cooperative learning model basically emphasizes students to work together in groups, and provides opportunities for groups to share the results and information obtained with other groups, so that the learning process will be student-centered. This study aims to achieve optimum student learning activities through the application of the Two Stay Two Stray (TSTS) model in learning the concepts of alpha, beta and gamma rays, and to describe the student's response to the TSTS cooperative learning that has been implemented. The method used is quantitative with the pre-experimental research model type one shot case study. A total of 26 students taking radiochemistry courses were the subjects of this study. Research data were collected through student activity observation sheets during lectures and a student response questionnaire consisting of 10 statements. The results of observations on student activities show that the aspect of explaining in the lecture material, the aspect of cooperation between colleagues, and the activity of answering questions, respectively, have a value of 86, 85 and 90 percent. In general, students' positive responses to the application of the TSTS model were 95%. From the research results, it can be concluded that the implementation of TSTS is very effective in increasing student learning activities, making students happy in learning, and fostering self-confidence in learning.