The rate at which atoms of radioactive sources (radionuclides) disintegrate are measured in ___________.

The rate at which atoms of radioactive sources disintegrate is measured in Curies, which is a unit that quantifies the activity of a radioactive material. One Curie is defined as the amount of a radioactive substance that undergoes 3.7 x 10^10 disintegrations per second. This measurement reflects the activity level of a radionuclide and is fundamental for understanding its potential radiation exposure and health effects.

The other options relate to different contexts in radiation protection. For example, Gray is a unit of absorbed radiation dose, measuring the amount of energy absorbed by a material per unit mass. Sieverts measure the biological effect of ionizing radiation, taking into account the type of radiation and its impact on health. "Banana equivalent doses" are a more informal way of conveying exposure levels by comparing them to the radiation one would receive from consuming bananas, which contain potassium-40, a naturally occurring radioactive isotope. However, they do not measure the rate of disintegration of radioactive sources.