What is the SI unit of dose?

The SI unit of dose is the Gray (Gy), which is used to measure the absorbed dose of radiation. It quantifies the amount of radiation energy imparted per unit mass of tissue; specifically, one Gray is defined as the absorption of one joule of radiation energy by one kilogram of matter. This unit is essential in the field of radiation therapy and dosimetry, as it provides a standardized way to assess how much radiation a patient receives, which is crucial for effective treatment planning and minimizing harm.

In contrast, the other options represent different concepts. The Becquerel (Bq) is a unit of radioactivity that indicates the rate of radioactive decay, specifically one decay per second. The Sievert (Sv) is used to measure the biological effect of radiation, taking into account the type of radiation and its impact on human tissue; it is a measure of dose equivalent rather than absorbed dose. The unit C/kg measures electrical charge per unit mass, which is not directly related to the absorbed dose of radiation. Understanding these units and their specific applications is vital for professionals in radiation therapy and medical dosimetry.