Activity

Key Stage 5

In radioactivity, activity is the number of disintegrations per second of a radioactive isotope.

Measured in becquerels (Bq), where 1 Bq equals one disintegration per second.
Indicates the rate at which a sample of radioactive material decays.
Higher activity means more frequent emissions of radiation.
Activity decreases over time as the radioactive material decays.
Related to the half-life of the radioactive isotope, which is the time taken for half of the isotope to decay.
Activity can also be measured in Curies (Ci), where 1 Ci = 3.7 x 10¹⁰ disintegrations per second.
Activity is used in various applications including medical imaging, cancer treatment, and radiometric dating.

Medical tracers have high activity to ensure they emit detectable radiation within a short time.
Radon detectors measure the activity of radon gas in homes to assess safety.