What is the SI unit of radioactivity?

The SI unit of radioactivity is the Becquerel. This unit quantifies the rate at which radioactive decay occurs, specifically indicating one disintegration or transformation per second. It is named after Henri Becquerel, who discovered radioactivity.

The Becquerel is a fundamental unit in nuclear physics and radiology, allowing scientists and medical professionals to measure and communicate the amount of radioactive material present in a substance. It is essential for safety standards and regulatory requirements concerning radiation exposure.

The other options represent different measurements related to radiation but serve different purposes. Gray measures absorbed radiation dose, Sievert assesses the biological effect of the absorbed dose, and Air Kerma is the measure of energy transferred from ionizing radiation to air. While all are important in the contexts of radiation and safety, they do not measure the rate of radioactive decay, which is the specific aspect that the Becquerel addresses.