What is the traditional unit of radiation absorption?

• A. Gray (Gy)
• B. Rad
• C. Rontgen (R)
• D. Sievert (Sv)

Answer: (B)

The traditional unit of radiation absorption is the rad. The rad is a unit that was historically used to quantify the amount of radiation energy deposited in a material, particularly biological tissues. One rad is defined as the absorption of 100 ergs of radiation energy per gram of matter.

This unit is important in understanding the biological effects of radiation, which makes it particularly relevant in fields involving radiation exposure, such as in medical imaging or radiation therapy. Although the gray has largely replaced the rad as the standard unit in the International System of Units (SI), the rad remains a recognized unit, especially in certain traditional contexts and older literature.

The other units mentioned serve different purposes: the gray is the SI unit for absorbed dose and is equivalent to 100 rads, the roentgen is a unit that measures exposure to gamma or X-rays in air, and the sievert is used to express the biological effect of radiation, taking into account the type of radiation and its impact on health. Each of these units is crucial in the field of radiation science, but they do not directly represent the traditional unit of radiation absorption like the rad does.