If a radiation dose is 5 rad, what is its equivalent in gray (Gy)?

• A. 0.5 Gy
• B. 0.1 Gy
• C. 0.05 Gy
• D. 1 Gy

Answer: (C)

To convert radiation dose from rad to gray, it's important to know the relationship between these units. The gray (Gy) is the SI unit of absorbed radiation dose, and it is defined as the absorption of one joule of radiation energy by one kilogram of matter. The rad is an older unit, where one rad is equivalent to 0.01 gray.

Given that 5 rad needs to be converted to gray, you would multiply the number of rads by the conversion factor:

5 rad * 0.01 Gy/rad = 0.05 Gy.

This confirms that a dose of 5 rad is equivalent to 0.05 gray. Understanding this conversion is crucial in both clinical practice and research, particularly in fields that involve radiation exposure, such as radiology and nuclear medicine.