金属钠跟水的反应非常激烈，钠被熔化成圆球，在水面上来回滚动，发出“滋、滋”的声音，放出氢气。此反应现象奇特，非常有趣。学生的情绪一下子就被调动起来，他们非常着急地想知道放出的气体是否为氢气。这时，教师应把反应的气体收集起来，并加以验证。现行的教材采用的是 The reaction of metal sodium with water is very intense. Sodium is melted into a sphere, rolling back and forth on the surface of the water, giving a “noisy, AIDS” sound and releasing hydrogen. This reaction is strange and very interesting. The students’ emotions were suddenly mobilized. They were very anxious to know whether the gas released was hydrogen. At this time, the teacher should collect the gas of the reaction and verify it. The current textbook uses