Surface contamination is usually expressed in units of radioactivity per unit of area.

A picocurie is one-trillionth of a curie, a unit of radioactivity.

The SI unit of radioactivity is the becquerel (Bq), equal to one disintegration per second.

This value derived from radium 226 was defined as unit of radioactivity known as Curie (Ci)

After Pierre's death, a group of scientists at the Radiology Congress decided to honour him by naming the unit of radioactivity a curie.

A picocurie is a unit of radioactivity, and the E.P.A. has recommended measures to lower radon levels in homes that are above the four-picocurie level.

The becquerel (symbol Bq) (pronounced: 'be-kə-rel) is the SI-derived unit of radioactivity.

The becquerel succeeded the curie (Ci), an older, non-SI unit of radioactivity based on the activity of 1 gram of radium-226.

The rutherford (symbol rd) is an obsolete unit of radioactivity, defined as the activity of a quantity of radioactive material in which one million nuclei decay per second.

The Curie (symbol Ci) is a non-SI unit of radioactivity, named after Marie and Pierre Curie.

Another unit of radioactivity is the curie, Ci, which was originally defined as the amount of radium emanation (radon-222) in equilibrium with one gram of pure radium, isotope Ra-226.

The curie (symbol Ci), a unit of radioactivity, is named in honour of her and Pierre (although the commission which agreed on the name never clearly stated whether the standard was named after Pierre, Marie or both of them).