What is the SI unit of in-air exposure?

The SI unit of in-air exposure is indeed Coulomb per kilogram (C/kg). This unit measures the amount of ionization produced by radiation in a specified amount of air. Specifically, it quantifies the charge of ions created when ionizing radiation passes through air, making it a crucial measure in radiation protection and exposure assessments.

In-depth, the use of Coulomb per kilogram stems from the need to have a standard measurement that reflects how much electromagnetic radiation interacts with matter—in this case, air. This interaction leads to ionization, which is significant for understanding the potential biological effects of radiation exposure.

To comprehend this concept better, it is important to note that exposure is directly related to the energy deposited in air by radiation as it interacts with atomic particles, thereby producing charged particles. By defining exposure in this manner, professionals can better estimate risks and apply appropriate protective measures when working with or around sources of radiation.