<prompt> Unit of radiation exposure ?GrayRoentgenSieveRed  <response>: Ans. is b i.e., Roentgen Units of potency Roentgen and coulomb per kilograme - Units of exposure. It is the amount to which a person is exposed. Red and Gray- Units of absorbed dose. It is the amount which is absorbed per gram of tissue. Rem and Sieve - Product of the absorbed dose and the modifying factor. Represent the degree of potention danger to health 