Light and the electromagnetic spectrum Study Guide

The electromagnetic (EM) spectrum is a continuous range of all possible frequencies of electromagnetic radiation. These waves are energy in different forms, travelling at the speed of light in a vacuum. Although they all share this fundamental nature, their varying wavelengths and frequencies lead to distinct properties and applications. The spectrum isn't neatly separated but rather flows from one type of wave to the next, with gradual changes in characteristics. Understanding its order is key to comprehending how different EM waves interact with matter and their uses in technology and the natural world.

For any object to maintain a constant temperature, it must be in a state of thermal equilibrium with its surroundings in terms of energy transfer. This means the rate at which the object absorbs thermal energy from its environment must precisely equal the rate at which it emits thermal energy. If an object absorbs more energy than it radiates, its internal energy will increase, leading to a rise in temperature. Conversely, if it radiates more energy than it absorbs, its internal energy will decrease, causing its temperature to fall. This balance ensures the net change in thermal energy of the body is zero, thereby keeping its temperature stable.