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目前,在中學化学教学中,讲解克分子、克原子,一般有两种方式。第一种是按照课文那样,说明“物质的一定量用克表示时在数值上等于它的分子量”,然后说明“任何物质的一克分子含有同数的分子”,过去我曾经这样讲过,一般同学感到难于接受,他们不明白为什么物质的一定量(就是不明白这一定量)要用克来表示(有的则认为过去提到物貭分子的重量不是用克来表示,而是用氧单位来表示,为什么现在又提出用克来表示呢?),特别是此一定量为什么又刚好在数值上等于它的分子量,如氧的分子量为32,則一克分子氧为32克,这32克是怎样来的呢?同学們是难以了解的。最后又提到一克分子的任何物貭里都含有同数的分子,同学们更是茫茫然了。尽管你用通俗的例子说明假定一个苹果是4两,一个桔子是2两,其重量不同,但它們的个数相同,一般同学还是不大相信一克分子的任何物质的重量可以不同而分子数完全相同的道理,因
At present, chemistry teaching in middle schools, explain gram molecules, grams of atoms, there are generally two ways. The first is that, as the text shows, “a certain amount of a substance is expressed numerically equal to its molecular weight in grams,” and then states that “a molecule of any substance contains molecules of the same number.” I used to say that in the past, Students feel difficult to accept, they do not understand why a certain amount of material (that is, do not understand the amount) to be expressed in grams (while others think that in the past the weight of molecules is not expressed in grams, but with oxygen units , Why is it now proposed to express in grams?), Especially why this certain quantity is just equal in value to its molecular weight. For example, if the molecular weight of oxygen is 32, 32 grams of one gram of oxygen is 32 grams How come? Students are hard to understand. Finally mentioned that one gram of molecules contained in the same number of molecules, the students is even more confusion. Although you use popular examples to illustrate the assumption that an apple is 4 two, an orange is 2 two, its weight is different, but their number is the same, the average classmate or not believe that the weight of any one gram of molecules can be different from the number of molecules Exactly the same reason