107 Stories About Chemistry |
There is logic in everything. Even the most unaccountable phenomenon has its logic It may not be perceptible at first, and then inconsistencies appear. Inconsistencies are very unpleasant things for any theory or hypothesis. They either disclose the wrongness of the theory or make one think hard. And it often so happens that this hard thinking helps to penetrate deeper into the uncomprehensible. Here is an example of such an inconsistency. Equality reigns only in the first two periods of the Periodic Table. There are exactly as many elements in each of these periods as the corresponding outer shell can hold electrons. Thus, in the atoms of the elements of the first period, hydrogen and helium, the K-shell is filled. It cannot contain more than two electrons, and therefore there are only two elements in the first period. An eight-electron (octet) shell fills up completely through the atoms of the elements of the second period, from lithium to neon, and that is why the second period contains eight elements. After this things get more involved. Count up the number of elements in the subsequent periods. There are 8 in the third, 18 in the fourth, 18 in the fifth, 32 in the sixth, and there should also be 32 in the seventh (which is incomplete as yet). But what about the corresponding shells? Here the figures are different: 18, 32, 50, and 72.
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