•a fraction of 一小部分 •on the basis of 根据……, 在……基础上
如果根据个别化合物来了解这么多化合
物的性质,即使其中的一小部分也是不可
能的。
.精品课件.
6
Fortunately, most chemical compounds can be grouped together in a few classes.
dቤተ መጻሕፍቲ ባይዱne on the basis of individual compounds. Fortunately, most
chemical compounds can be grouped together in a few classes.
Then, if we can properly classify a compound, we are at once
usually a metal. Ex., NaOH, Ca(OH)2, Fe(OH)3.
3. A salt consists of a metal, written first, combined
with a non-metal or radical written last in a formula.
• be aware of 知道,意识到……
那么,如果我们能够恰当地将一个化合物归类,我们立
刻就能从这类化合物的性质来了解这个化合物的一般性 质。
.精品课件.
8
For example, HCl is classed as an acid, and by becoming familiar with the behavior of acids as a distinct class, we are at once aware of the general properties of the compound.