What is the reference definition of a curie?

What is the reference definition of a curie?

• A. The activity of 1 gram of radium-226 in one second
• B. The energy released per decay
• C. The dose rate in sieverts per hour
• D. The half-life of radium-226

Answer: (A)

Curie is a unit of radioactivity that measures how many decays occur per second. The reference definition ties it to radium-226. Historically, one curie was defined as the activity of 1 gram of radium-226, which corresponds to 3.7×10^10 disintegrations per second. In modern terms, activity is expressed in becquerels, where 1 curie equals 3.7×10^10 Bq (about 37 GBq). This unit concerns decay rate, not energy released per decay, dose rate, or half-life. So describing the curie as the activity of 1 gram of radium-226 in one second aligns with its historical definition.

Curie is a unit of radioactivity that measures how many decays occur per second. The reference definition ties it to radium-226. Historically, one curie was defined as the activity of 1 gram of radium-226, which corresponds to 3.7×10^10 disintegrations per second. In modern terms, activity is expressed in becquerels, where 1 curie equals 3.7×10^10 Bq (about 37 GBq). This unit concerns decay rate, not energy released per decay, dose rate, or half-life. So describing the curie as the activity of 1 gram of radium-226 in one second aligns with its historical definition.