Among them was a radioactive form of cobalt, which rapidly transforms itself into iron.

Scientists applied the radium work to research with other radioactive forms of elements, called isotopes.

In August 2009, workers found and stopped two small leaks of tritium, a radioactive form of hydrogen.

Radionuclide: an unstable and therefore radioactive form of a nuclide.

Cesium-137 is the most common radioactive form of the metal cesium.

Cosmic rays produce carbon-14, a radioactive form of carbon, in the higher regions of the atmosphere.

Tritium is a radioactive form of hydrogen that loses half its radioactivity every 12.4 years.

He developed a detector for decays of carbon-14, a radioactive form of carbon, that can be used to this end.

A radioactive form of strontium may kill some cancer cells.

Federal officials and the plant's owners say there is no danger from the leaking water, which contains tritium, a radioactive form of hydrogen.