投影实验具有操作简单、药品用量少、污染小、灵敏度高、可见幅度大、能形象生动地反映某些实验现象等特点,这是许多常规演示实验无法比拟的,因此备受教师青睐。合理运用投影实验,能放大现象、节约药品、增强实验效果,体现化学实验的魅力,激发学生学习化学的兴趣。一、放大现象,体现化学之美有些演示实验现象不明显,坐在后面的学生较难观 Projection experiments with simple operation, less dosage, less pollution, high sensitivity, visible range, can vividly reflect some of the experimental phenomena and other characteristics, which is unmatched by many conventional demonstration experiments, so much teachers favor. Rational use of projection experiments can amplify the phenomenon, save drugs, enhance the experimental results, reflect the charm of chemical experiments, stimulate students interest in learning chemistry. First, the phenomenon of amplification, reflecting the beauty of some experiments demonstration of the phenomenon is not obvious, sitting behind the more difficult view