Periodicity

Periodicity is the quality of occurring at regular intervals or periods (in time or space) and can occur in different contexts:
* A clock marks time at periodic intervals.
* A metronome ticks at periodic intervals of time.
* A publication published at periodic intervals can be called a "periodical", for example a magazine.
* In mathematics, a function whose output contains values that repeat periodically is called a periodic function.
* In chemistry, the periodic table is a table which classifies the chemical elements by means of the periodicity of their chemical properties.
* In physics, period is the number of cycles as a result of time (time/cycle). The amount of time it takes to complete one full revolution. Period is also the inverse of frequency.
* In music theory, periodicity is described as "predictability gives rise to expectations".
* Standing waves crest at periodic intervals of distance.
* In finance, the periodicity of a loan describes the interval between payments.
* The measure of periodicity in time is frequency which has the metric units of Hertz.

ee also

* Cycle
* Frequency (disambiguation)
* Simultaneity
* Synchronicity
* Utility frequency