Becquerel

Part of speech: noun

Pronunciation: [bɛkəˈɹɛɫ]

Definitions

1. A unit of radioactivity equivalent to one disintegration per second, used to measure the decay of radioactive atoms
2. A measure reflecting the rate of any radiation given off by a radioactive material, defined as one decay event per second
3. A standard unit indicating the activity of a radioactive isotope, representing one radioactive decay occurring in one second

Etymology: The becquerel was named for Henri Becquerel, the French physicist who discovered radioactivity in 1896 while studying uranium salts, which he found could darken photographic plates even in the dark. The unit was adopted in his honour in 1975 by the General Conference on Weights and Measures, a body that also gave the SI system its name. Becquerel shared the 1903 Nobel Prize in Physics with Pierre and Marie Curie for this work. The name passed into English as a borrowing from French, where the physicist's surname had already been fixed as a scientific label. English speakers use it as a unit, so the word carries no separate sense beyond measuring decay. Its counterpart, the curie, is named after Marie and Pierre Curie, which makes the pair of units a tribute to the researchers who first made radioactivity measurable.