Lou Liebovich, age 16, of Rockford, Illinois, for his question:
Have the series of actinide elements any uses?
Most of these radioactive elements are man made and the cost of producing them in pinch sized samples is enormous. One of the easiest can be made to sell at just under half a million dollars an ounce. Two of the actinides, however, are more plentiful. When properly used, they may remodel our entire everyday world for the better.
This series of chemical elements has a column of its own on the Periodic Table. The parent of the actinide family is actinium and the other 14 elements in the group closely resemble it. Their atomic numbers range from actinium 89 to lawrencium 103. The actinides are big, unstable atoms and all of them are radioactive. They share the same types of chemical behavior because their electron patterns are so similar. Each actinide has seven electron shells with two electrons in the seventh shell and either eight, nine or 10 in the sixth shell.
Their outstanding feature is radioactivity. Their atoms are breaking apart at fixed rates into smaller and still smaller atoms. Each miniature atomic fission shoots a particle from the nucleus, releasing a quota of dynamic nuclear energy. All the actinides emit piercing rays of alpha, gamma and beta particles and they must be handled with care. But energy of any sort is power and man can use his brains to tame it and use it to suit himself. The actinide series contains the most dynamic nuclear fuels so far discovered.
Since a radioactive substance is decaying into something else, its useful life span is limited. This span is measured by the half life unit. After each half life period, half of the radioactive substance has decayed. Half of the rest decays in the next half life. The actinides have half lives ranging from a few moments to 4 1/2 billion years.
This staggering half life belongs to uranium, the grandfather element of the Atomic Age. Fuels refined from uranium ores yield millions of times more energy than coal and oil. Uranium and thorium are the only actinides found in usable quantities in nature. Uranium makes up less than 1/1,000 of a per cent of the earth's crust and thorium is only a little more abundant. Nuclear physicists can transmute thorium into a type of uranium for use in atomic power plants. They also can make it yield mesothorium that glows in the dark. Mesothorium now replaces costly radium on clock dials and in luminous paints. The piercing rays of radioactive substances can detect flaws in metals and perform a wide range of otherwise impossible chores in industry. All but two of the actinides, however, are among the rarest elements known. Actinium is the earth's second rarest element. Protactinium is the third rarest, though nuclear physicists can make it at a cost of about $15,000 a gram. All the actinides teem with useful energy.
Even the rarest actinides are kept busy behind the scenes in the world of research. The energy and flying particles from tiny samples can cause changes in atomic structures and even transmute one metal into another. This research advances the science of physics. A tiny trace of einsteinium led to the discovery of lawrencium, the latest actinide. At present, these rare actinides are used for research but they are full of promises for astonishing uses in the future.