Gloria Zermeno, age 15, of Houston, Texas, for her question:

What is berkelium?

The University of California at Berkeley is the home of a world famous radiation lab. Scientists there have detected at least 11 atomic elements that are heavier than uranium, which is the heaviest element found in nature. Berkeley, one might say, is the rightful birthplace of most of the man made atoms. It seemed only fair to name one of them in honor of the place. The name berkelium was chosen for element number 97.

All the heavy elements in this family are unstable and highly radioactive. Complicated and expensive techniques are necessary to produce merely a few atoms and in most cases half of them decay in a very short while. Berkelium was discovered and identified as a new man made element in 1949. Since then cyclotrons have been used to create a few traces by bombarding americium, element 95, with high speed alpha particles. The small samples of berkelium provide useful clues to physicists. But so far nobody has found a marketable use for this heavy, unstable element.