在现行化学实验中 ,有一些实验现象和结果与理论预测不吻合。有的学生很认真 ,发现疑点后能积极询问 ,教学实践中我感到 ,正面回答学生不如旁敲侧击 ,引而不发给学生留下思考的余地 ,鼓励他们去争论 ,在争论中去找答案。下面选出两例和大家一起探讨。第一例是在《碱金属和卤素? In the current chemical experiments, some experimental phenomena and results do not coincide with theoretical predictions. Some students are conscientious. When they find doubt, they can ask actively. In the teaching practice, I feel that it is better to give students a better answer than to give students a chance to think. Encourage them to argue and find answers in the debate. The following two cases were selected to discuss with everyone. The first case is in "Alkali and Halogen?