Chemical phenomena can be explained by three levels of representation, namely macroscopic, sub microscopic and symbolic. Chemistry learning media which includes three dimensions of representation can make it easier for students to build chemical concepts. The aim of this research is to produce a valid multipeld representation-based media on electrolyte and non electrolyte solution course, to know students respond toward multipel representation-based media on electrolyte and non electrolyte solution course that developed. This study was categorized as research and development (RnD). The media development procedure used in this research through 7 phase and adapted from Borg & Gall development model.  The collecting data procedure used are interview and questionnaire. This research involve 2 material experts, chemistry teacher and expert lecturer, 1 media expert and 1 language expert. The subject of this research involve 6 students for small scale research and 30 students for medium scale research. The result of this study showed the developed media is valid and appropriate to use with detail score; 4 from experts lecturer (very good), 3.55 from chemistry teacher (very good), 3.46 from media expert (very good), 3.55 from language expert (very good), while students respond in small scale research get score percentage 90% (really agree) and students respond in medium scale research get percentage score 90.5% (really agree)

Corrosion is spontaneity and unavoidable reactions which cause degradation in the quality of the materials. Most industries have been harmed by the corrosion of manufacturing equipment. Several methods can be applied to control this problem. The use of corrosion inhibitors is an effective and practical way to decrease metal deterioration significantly. Many commercial inorganic and organic compounds are effective inhibitors, but most of them are not completely safe and relatively expensive. Carbon dots and their derivatives are potential compounds for resolving corrosion reactions on metal surfaces. Carbon dots can be synthesized from various natural sources to be more environmentally friendly. This systematic review aims to summarize the concept of corrosion, types of carbon dots-based corrosion inhibitor and their effectiveness on various metals, inhibition mechanism, surface analysis of the protected metals, kinetics, thermodynamics, and quantum computational chemistry studies. This review also presents the significance and the prospects of carbon dots-based corrosion inhibitors.

The quality of education depends on competence of teachers in managing learning. Improving the quality of learning in class can improve the quality of education. Research conducted using classroom action research with  qualitative descriptive approach thats aims to find out and describe the application of the ARIAS learning model in improving students' cognitive abilities. Subjects in the study were teachers and all students of class XI IPA 2 SMA Negeri 6 Palembang. The instruments used in the research were questionnaires, observation sheets, cognitive ability tests and documentation studies. Based on the treatment given by the teacher for three cycles, it was found that the average cognitive chemical ability of students in the first cycle was 69,66. In the second and third cycles, the average chemical cognitive abilities of students were 78,84 and 84.35. Meanwhile, the percentage of learning mastery obtained in the first, second and third cycles were 52,63%, 73,68%, and 86,84%. Based on the research and data analysis conducted, it is known that the ARIAS learning model can improve students' cognitive abilities. Besides that, it can develop students' self-confidence and enthusiasm in learning chemistry.

The Covid-19 virus in Indonesia has caused face-to-face learning switching to online learning. In the 2013 curriculum there is skill competency, so that in learning chemistry to achieve that, practicum activities are carried out at home and environmentally friendly. This research is an R & D (Research and Development) aimed to knowing the level of validity and knowing response of students to an electronic practicum guide based on green chemistry with the learning cycle-7e learning model on acid-base material. The development and research procedure uses the ADDIE model, due to the limited time the stages carried out are ADD (Analysis, Design, and Developme). The study involved four validators, namely one media expert validator, one language validator, and two material expert validators. The trials carried out are one to one and small group. The subjects were students of SMA Muhammadiyah 1 Palembang. Data collection instruments used validation sheets and student response questionnaires. Data analysis used qualitative and quantitative analysis. The results of this study indicate that the green chemistry-based electronic practicum guide with the learning cycle-7e learning model on acid-base material is very valid based on the validation results of material, media, and language experts with an average percentage obtained of 83.5%. The students' responses were categorized as very good, where in the one-to-one trial percentage is 98.6% in the very good category, in the small group trial the percentage is 95.2% in the very good category.