Student Worksheet Development to Practice Critical Thinking Skill Using Blended Learning on Reaction Rate

ABSTRACT: This research aims to determine the feasibility of student worksheets practice critical thinking skills using blended learning on reaction rate matter. is Research & Development (R&D) design with subjects are 2nd-grade students. The instrument used which as worksheet, pretest-posttest sheet, activity observation, and responses questionnaire. validity concentration factor, surface area, temperature, catalyst obtained percentage respectively 89.37%, 87.55%, 87.67%, 87.53%. Student activities, obtaining a 90% observation by 91%. effectiveness students' in terms N-gain score pretest posttest an average 0.65 medium category very effective skill. So worksheet guided inquiry model strategy matter skill feasible use High School.Keywords: skill, learning,