化学课伊始,我们先要区分两个容易混淆的变化。物理变化和化学变化像水加热成水蒸气,蜡受热熔化等都是物理变化,因为虽然物质的形状发生了变化,但并没有生成其他物质。化学变化的区别就在于有新的物质生成,比如银白色的镁带燃烧生成了白色的氧化镁粉末。 At the beginning of chemistry class, we first distinguish between two easily confused changes. Physical changes and chemical changes Like water heated to steam, melted wax and other physical changes are due to changes in the shape of the material, but did not generate other substances. The difference between chemical changes is that there is a new material generation, such as white magnesium oxide powder generated by the combustion of silver-white magnesium.