12/27/1996 08:00:00

Question of the Week: Could There Possibly Be New Elements In the Universe That Haven't Been Detected?

Question of the Month Submitted by Rick Conner, Laguna Niguel, and answered by Donald Burnett, Professor of Geochemistry, Caltech.

The answer is yes.

Elements are numbered according to the number of protons they contain. For example, hydrogen, the first element on the periodic table, has one proton. Oxygen has eight, iron has 26, and gold has 79. Uranium, with 92 protons, is the heaviest element that has been detected elsewhere in the universe by astronomers.

The current periodic table contains about 107 elements, but the ones heavier than uranium have been detected only after being artificially produced in the laboratory. Elements 100 through 107 are especially unstable and difficult to make. Only a few atoms of each have been produced, and these are radioactive, decaying in a few seconds or less.

Theoretically, however, elements having atomic numbers in the range of 109 through 114 should be comparatively stable. In fact, one or more of these "island of stability" elements could exist for a year, or perhaps even billions of years, before decaying.

What we do know is that, for the elements below 100, nature has produced all possible stable nuclei. All of the elements can be produced in the burning processes of stars, but many nuclei heavier than iron—and uranium in particular—are made by spectacular processes such as supernova explosions. And since every single element through uranium can be found both on Earth and elsewhere in the universe, the question is whether nature has filled in the elements between 109 and 114 as well.

Many searches have been made, but natural superheavy elements have not been found. This may mean that the lifetimes of the superheavy elements are relatively short, or that concentrations of superheavy atoms are so small that they were missed, or that there is no way to synthesize superheavy elements in stars.

So the final answer to your question will be left for advanced science of the 21st century.