Which unit of measurement is equivalent to the exposure of 1 coulomb/kg?

The unit of measurement equivalent to the exposure of 1 coulomb/kg is the Roentgen. This particular unit measures the exposure to ionizing radiation and is specifically defined based on the amount of ionization produced in air by X-rays or gamma rays.

When 1 coulomb of electric charge is deposited in 1 kg of air, it corresponds to the amount of radiation required to produce a certain level of ionization, which is what the Roentgen quantifies. Thus, the Roentgen is directly related to the measurement of exposure due to ionizing radiation and is often used in radiological contexts to assess the level of exposure a person or an environment has been subjected to.

In contrast, other units mentioned serve different purposes in radiation measurement. Gray measures the absorbed dose of radiation in a material, Sievert accounts for the biological effect of radiation, factoring in type and energy, and Becquerel represents radioactivity, indicating the number of decay events per second in a substance. Each of these units is important in the field of radiology, but when it comes to ionizing exposure specifically defined by coulombs per kilogram, the Roentgen is the correct and relevant measurement.