Abstract
The achievement of the competence of class XI students in learning Physics was not yet optimal. One of the contributing factors was that the available student worksheets (LKPD) did not contain the model steps and learning approaches that led it to the student activities. This study aimed to produce LKPD using an inquiry-based learning model that integrated creative thinking skills with a scientific approach in 21st century physics learning for class XI semester 1 with valid, practical and effective criteria. This type of research was development research using the Plomp model with three phases, there were preliminary research, development or prototyping phase, and assessment phase. Research instruments included preliminary study questionnaires, validity questionnaires, practical questionnaires, observation sheets, written tests, and skills assessment sheets. Meanwhile the technique for effectiveness analysis , it used the descriptive percentages for analysis of effectiveness in terms of skills and Normalized Gain (N-gain) for percentages for cognitive effectiveness analysis. The results of the effectiveness of the use student worksheet at the assessment phase show that the achievement of student competence through N-gain calculations is 0,8. Thus, it could be concluded that the student worksheet using an inquiry-based learning model that integrated creative thinking skills with a scientific approach in physics learning in the 21st century class XI SMA met the effective criteria.