先讲物质的性质,而后讲物质的制法和用途,是学习苏联先进教学方法的一种。而初中化学课本就采用了这种方法,这样不但能启发学生积极地思考,同时还能加深记忆,而不至于死记硬背,这样在未上课以前,就必须先制出这种物质,在课堂上才能边讲边作实验,而达到理论与实际相结合的目的。像讲二氧化碳,就需要事先制出几瓶以后,在课堂上叫学生观察实验二氧化碳的状态、颜色和臭味。再实验它比空气重、有灭火性,更进一步来证明二氧化碳是酸性氧化物,溶于水使石芯试纸变色,及对碱(氢氧化钠水溶液)的作用。但第一堂课可以在堂下制备几瓶,以备使用,要是一连二课或三课那就会发生困难,若在下课后的十分钟进行制备,虽然也可以,但时间短很紧张,不能使教师很好的休息,因此,也会影响下一堂课的情锗。所以在这一点上,我作了长时间的考虑,也作了实验,我觉 Talking about the nature of matter, and then speaking of the material system of law and use, is to learn advanced Soviet teaching methods. The junior high school chemistry textbook to adopt this method, so that not only inspire students to think actively, but also deepen the memory, rather than rote, so that before the class must be made of this material, in the classroom In order to experiment while talking, and achieve the purpose of combining theory with reality. Like to talk about carbon dioxide, you need to make a few bottles later, in the class called the students to observe the experimental state of carbon dioxide, color and odor. Re-experiment it is heavier than the air, a fire-extinguishing, and further to prove that carbon dioxide is acidic oxide, dissolved in water to make stone core paper discoloration, and alkali (sodium hydroxide solution) role. However, the first lesson can be prepared in the hall a few bottles to prepare for use, if two or three lessons that will be a difficulty, if after ten minutes after class preparation, although it is OK, but the time is short and tight, Can not make teachers a good rest, therefore, will also affect the next class of German. So at this point, I made a long time of consideration and experimented. I think