What does radiation refer to in physical science?

In physical science, radiation refers to the transfer of energy through electromagnetic waves. This process involves the emission and propagation of energy that can travel through a vacuum or different mediums. Unlike conduction or convection, which require material substances to transfer heat, radiation allows energy to move through space without the need for a physical medium. Examples of radiation include visible light from the Sun, infrared radiation felt as heat, and other forms of electromagnetic radiation such as X-rays and gamma rays.

The other options describe different physical processes: conduction pertains to heat transfer via direct contact between materials, convection involves the movement of fluids that carry heat within them, chemical bonding refers to the interactions that hold atoms together in molecules, and changes in the state of matter involve phase transitions between solid, liquid, and gas. Therefore, only the transfer of energy through electromagnetic waves accurately defines radiation in the context of physical science.