Stories About Chemistry
107. Ghosts that Serve
Here is a fact likely to cause a sensation in the newspapers: a renowned scientist is presented by his grateful colleagues with a vase made of ... aluminium. One should be thankful for any present, but to give an aluminium vase as a present... what an excellent subject for sarcasm. ... So would it be now, but a hundred years ago such a present seemed exceedingly generous. As a matter of fact, an aluminium vase actually was presented by English chemists and not just to anyone, but to D. Mendeleyev himself. It was presented to him in acknowledgement of his great services to science.
See how relative everything is in this world! In the last century no cheap method of producing aluminium from its ores was known. And the metal was therefore expensive. When such a method was found, the price dropped abruptly.
Many elements of the Periodic System are far from cheap even today, which limits the range of their practical applications. But we are certain that this situation will not last. Chemistry and physics will “cut the prices” of the elements more than once. They are sure to do this because practice is drawing more and more inhabitants of the Periodic Table into the sphere of its activities.
But there are elements which either do not occur in the Earth’s crust or occur in such insignificant quantities that one might say there was practically none of them. Such are astatine and francium, neptunium and plutonium, promethium and technetium...
However, these elements can be prepared artificially. And insofar as a chemist has a new element at his disposal he begins to think of what to do to start it on its path to life.
So far, the practically most important artificial element is plutonium. And accordingly, its world production now exceeds that of many of the “ordinary” elements of the Periodic System. It may be added that chemists class plutonium as one of the best known elements, though it is only a little over a quarter of a century “old.” This is no accident, because plutonium is an excellent “fuel” for nuclear reactors, not inferior to uranium.
The energy source on some of the American Earth satellites was americium and curium. These elements are noted for very powerful radioactivity and liberate a great deal of heat when they decay. Thermocouples transformed this heat into electricity.
And what about promethium, which has not been found so far in terrestrial ores? It has gone into the manufacture of miniature batteries a little larger in size than the head of an ordinary thumb tack. The very best chemical batteries last for not more than half a year. The promethium atomic battery operates continuously for five years, and its applications range from hearing aids to guided missiles.
Astatine offers its services to physicians for fighting diseases of the thyroid gland. Attempts are now being made to cure thyroid disorders with the aid of radioactive radiations. Iodine is known to accumulate in the thyroid and astatine Is the chemical analogue of iodine. Introduced into the organism, astatine concentrates in the thyroid gland, and its radioactive properties do the rest. Thus, some of the artificial elements are by no means devoid of practical uses. True, their service to mankind is one-sided, because people can make use only of their radioactive properties But this is only because chemists have not yet got down to their chemical properties. An exception is technetium The salts of this metal have been found to make iron and steel articles very resistant to corrosion.