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Students think that chemistry was a difficult subject. Students' learning achievement influence of several factors. Critical thinking skills can influence the students' learning achievement. This research aims to identify the critical thinking skills of tenthgrade students. They are high, medium, and low critical thinking skills that can be identified using the Cornell Critical Thinking Test (CCTT). Survey method as the research method. The data was collected by the test in three schools with high, medium, and low grades. The result showed that there were 35.5% with high critical thinking skills, 45.2% with medium critical thinking skills, and 19.3% with low critical thinking skills (high grade school); 25% with high critical thinking skills, 56.25% with medium critical thinking skills and 18.75% with low critical thinking skills (medium grade school); 18.75% with high critical thinking skills, 37.5% with medium critical thinking skills and 43.75% with low critical thinking skills (low grade school). This research can be used as a reference to improve students' critical thinking skills.

Despite its important role in science education as major reference supporting teaching and learning activities at schools, there have not been many researches focusing on investigating the quality of science textbook content. Science subjects, such as chemistry, are way more susceptible to errors because the need of more analysis and deduction activities rather than mere information gathering. This present, descriptive study examined the presence of misconceptions in the 12th grade chemistry textbooks on Redox and Electrochemistry. Each textbook was examined page by page based on document analysis method. The research samples consist of 2 textbooks obtained through purposive sampling. The founded misconceptions divided into 5 categories: oversimplifications, overgeneralizations, obsolete concepts and terms, misidentifications, and flawed research. The results showed that there are 13 misconceptions found in textbooks, namely: 7.7% oversimplifications, 30. 8% overgeneralization and 61.5% misidentifications. Based on the analysis, misidentifications are the most common misconceptions found both in book A and book B. These findings may provide a platform to improve the quality of textbooks preparation in particular and education in general.

Several essential oils have been evaluated as antibacterial agent in the production of natural paper from banana peel (Musa paradisiaca Linn.), namely cinnamon, clove, lime and lemon oil. The purpose of the research was to examine the antibacterial activity of the papers with additive of those several essential oils againt Staphylococcus aureus and Escherichia coli. Paper preparation was successfully carried out by alkalization method, using 4% NaOH at a temperature of 100 °C for 1 h. The essential oils as antibacterial agent were added with concentration 2.5% to the pulp (1:40). The antibacterial activities were tested using Kirby-Bauer disc diffusion method. All of the paper produced meet the standard of ISO 6519:2016 about Basic Paper for Laminated Plastic Wrapping Paper within the parameter of pH and water content. The result of the research showed that all of the paper with essential oils additive has antibacterial activity againt S. aureus, but only paper with cinnamon oil additive that have antibacterial activity againts E. coli. The use of cinnamon oil gave the largest inhibition zone diameter both on S. aureus and E. coli. Paper with cinnamon oil additive had inhibition zone diameter 18 mm on S. aureus (strong category) and 9 mm on E. coli (medium category).