👉 In physics, a medium is an object or substance that can transmit light and other types of electromagnetic radiation. It can be made up of solids, liquids, gases, or combinations of these substances. The properties of a medium determine its ability to transmit light, heat, and sound. Matter in the form of matter is classified into several categories based on its physical characteristics: 1. Solid: Materials that have a fixed shape or are solid at room temperature. Examples include metals (like copper and iron