AU - دنيور، يسرى طه محمد. AB - This study aimed at recognizing the effect of using problem based learning in teaching science on the achievement and development of reflective thinking skills and motivation towards learning science for the second grade prep school students , the sample of the study consisted of second prep grade students (n= 80) at Ahmed Helal Shona prep school at Dakhlia . The sample was divided into two groups: the experimental group that consists of (40) students, and the control group that consists of (40) students. The tools of the study were achievement test in science, reflective thinking test and motivation scale towards learning science , the researcher who prepared all these tools. The tools of the study were applied before teaching, then the unit (sound and light)was taught for the experimental group by using problem- based learning, while the control group studied by using the traditional method. After finishing teaching unit, researcher has applied the tools of study. The results of the study were: there were statistically significant differences at the level of (0.05) between the mean scores of the experimental group students who studied by using problem based learning and the control group students who studied using traditional method on the post- application of the achievement test , the reflective thinking and motivation scale towards learning science in favor of the experimental group students, there was statistically significant relationship between the achievement of science and reflective thinking, and between the achievement of science and motivation towards learning science, and between reflective thinking and motivation towards learning science. The study introduced recommendation and suggestion for further research. (Published Abstract) http://search.shamaa.org/abstract_en.gif ID - 125326 OP - ص ص. 15-67 T1 - أثر استخدام استراتيجية التعلم المتمركز حول المشكلة في تنمية التحصيل والتفكير التأملي والدافعية نحو تعلم العلوم لدى تلاميذ الصف الثاني الإعدادي [مقال] UL - 1 http://search.shamaa.org/fulltext.gif http://search.shamaa.org/PDF/Articles/EGAsep/AsepNo73Y2016/asep_2016-n73_015-067.pdf النص الكامل (PDF)