What term describes the distance from trough to trough on a periodic wave?

The term that describes the distance from trough to trough on a periodic wave is referred to as wavelength. Wavelength is defined as the physical length of one complete cycle of a wave, which can be measured from one trough to the next trough, or from one crest to the next crest. This distance is a key characteristic of waves and determines various properties, such as frequency and energy.

Understanding wavelength is essential in physics as it relates closely to the behavior of waves in different media and their interactions with various elements in the environment. In contrast, amplitude refers to the maximum displacement of points on a wave from the rest position, while frequency measures how many cycles of the wave pass a point in a given time, and crest denotes the highest point of a wave. Thus, among the provided terms, wavelength specifically pertains to the distance measurement between similar points on successive cycles of the wave.