Absorbed dose is defined as the energy imparted to matter by the ionizing radiation per unit mass of material at the place of interest.

Absorbed dose is defined as the energy imparted to matter by the ionizing radiation per unit mass of material at the place of interest.

• A. The energy imparted to matter by the ionizing radiation per unit mass at the point of interest.
• B. The rate at which energy is deposited per unit area at the source.
• C. The total energy emitted by the radiation source per unit time.
• D. The dose rate in rem per hour.

Answer: (A)

Absorbed dose is the energy deposited by ionizing radiation in a material divided by the mass of that material at the location where the energy is deposited. This focuses on how much energy actually stays in and interacts with the matter you’re considering, normalized to how much matter there is to absorb it. The unit gray (Gy) reflects joules per kilogram, so a higher energy deposition in a smaller mass means a larger dose. The statement matches this idea exactly: it describes energy imparted to matter per unit mass at the point of interest. The other options describe different quantities that aren’t absorbed dose. A rate of energy deposition per unit area at the source mixes area with energy, not mass, so it isn’t absorbed dose. The total energy emitted by the source per unit time is a measure of power, not dose. A dose rate expressed in rem per hour gives how fast dose would accumulate and uses a different unit (rem) tied to dose equivalent, not the absorbed dose itself.

Absorbed dose is the energy deposited by ionizing radiation in a material divided by the mass of that material at the location where the energy is deposited. This focuses on how much energy actually stays in and interacts with the matter you’re considering, normalized to how much matter there is to absorb it. The unit gray (Gy) reflects joules per kilogram, so a higher energy deposition in a smaller mass means a larger dose.

The statement matches this idea exactly: it describes energy imparted to matter per unit mass at the point of interest. The other options describe different quantities that aren’t absorbed dose. A rate of energy deposition per unit area at the source mixes area with energy, not mass, so it isn’t absorbed dose. The total energy emitted by the source per unit time is a measure of power, not dose. A dose rate expressed in rem per hour gives how fast dose would accumulate and uses a different unit (rem) tied to dose equivalent, not the absorbed dose itself.