This research aims to develop an E-LKPD (Electronic Student Worksheet) based on REACT (Relating, Experiencing, Applying, Cooperating, Transferring) using Wizer.me for the topic of Thermochemistry for 11th-grade high school/equivalent students that is valid based on several assessment aspects. The method used is R&D with the ADDIE model (Analysis, Design, Development, Implementation, Evaluation)…