Student worksheets are one sort of educational material intended to aid students' learning, explore experiences and ideas, and develop students' cognitive, psychomotor, and affective components. As a result, a study of the validity and applicability of the Student Worksheet on waves and sound content for junior high school students was done. The goal of this study was to see if the Student Worksheet was reliable and practical. The research design used in this study is a developmental study. A walkthrough and a questionnaire were employed as research tools. The validity test was said to be quite valid based on the average content aspect of 4.71, language 4.70, and design 4.78, according to the study's findings. While the practicality test was stated to be very practical, the results obtained one to one teacher on the average content aspect of 5, language 5, and design 5. One to one students obtained an average of 4.73 content aspect, 4.33 language, and 4 design ,55. The results of the practicality of the small group of teachers on the aspect of content are on average 4.11, language 4.66, and design 4.44. The small group of students obtained an average of 4.22 in the aspect of content, 4.52 in language, and 4.36 in design. So it can be concluded that the Student Worksheet material waves and sounds for junior high school is very valid and very practical. Furthermore, it can be used for the effectiveness test stage

The background of the research is that skills are needed in accordance with the era of the industrial revolution 4.0, especially in the 21st century, namely critical thinking skills. For this reason, research is needed to determine the description of critical thinking skills. This research is a preliminary study that aims to describe the ability of critical thinking skills in learning science physics. Descriptive research method using google form. The research subjects were 33 students of SMP Negeri 59 Palembang. The results obtained are 25% of students are able to focus questions, 30% analyze questions, 32% consider reliable sources or not, 17% observe, consider observation reports, 39% do and consider deduction results, 38% do and consider induction results, 42% make and determine the value of judgment, 25% define, consider definitions, 21% identify assumptions, 44% determine actions, and 54% interact with others. The description of the critical thinking skills of junior high school students in the 4.0 industrial revolution era Physics science material is still in the low category, judging by the percentage of student responses. Suggestions for further research on efforts that can overcome the low critical thinking skills of junior high school students on Physics Science material.