Curie (Ci)

Definition

The curie (Ci) is a unit of radioactivity, defined as the quantity of any radioactive substance in which 3.7 × 10^{10} disintegrations occur per second. It is named after the pioneering scientist Marie Curie.

5 Must Know Facts For Your Next Test

1. 1 Ci equals 3.7 × 10^{10} disintegrations per second.
2. The curie measures the intensity of radioactivity, not the biological effect or energy emitted.
3. It was originally based on the activity of 1 gram of radium-226.
4. The SI unit that has largely replaced the curie is the becquerel (Bq), where 1 Ci = 3.7 × 10^{10} Bq.
5. Curie is commonly used in medical applications and radiation therapy to quantify radioactive sources.

Related terms

Becquerel (Bq): The SI unit for measuring radioactivity, defined as one disintegration per second.

Radium-226: A radioactive isotope originally used to define the curie; it emits alpha particles and has a half-life of about 1600 years.

Disintegration: (In nuclear chemistry) The process by which an unstable atomic nucleus loses energy by emitting radiation.