107 Stories About Chemistry |
What would you say about a contractor who erected a building and after putting the roof on, asked the designers to calculate whether everything had been done right? It sounds like an episode from "Through the Looking Glass," doesn't it? Nevertheless that was just what happened to the Periodic System of Elements. The Big House was first built and the elements lodged, each in a flat of its own. Chemists made Mendeleyev's Table their tool. But why the properties of the elements repeat themselves periodically they could not tell for a long time. The explanation was supplied by the physicists. They calculated the structure of thePeriodic System building for strength, and their findings were remarkable. They found it to have been built absolutely right in accordance with all the laws of "chemical mechanics:" And so we cannot but admire Mendeleyev's truly great intuition and profound knowledge of chemistry. Physicists began by studying the structure of the atom in detail. The heart of the atom is its nucleus. Around it revolve electrons, the number of which equals the number of positive charges on the nucleus. Hydrogen has one electron, potassium has twelve, uranium has ninety-two. How do they revolve? Chaotically, like a swarm of moths fluttering around an electric light bulb, or in some definite order?
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