Yet as an element of contamination, "the radioactive atom remained supreme."

The radioactive atom supplies a signal that can be monitored.

Most materials on Earth contain some radioactive atoms, even if in small quantities.

Many compounds with the radioactive atoms in specific positions can be prepared, and are widely available commercially.

No one can predict when a given radioactive atom will decay.

If you "label" a molecule with a radioactive atom its location in the body will show up on an X-ray.

Gamma rays are produced by some types of radioactive atoms.

At the top is a radioactive atom which envelops a man in smoke.

A radioactive atom, say, can be both decayed and undecayed.

Glucose can be labeled with either stable or radioactive atoms.