Cycle per second operation. Thus, one becquerel is one event per second "on average", whereas one hertz is one event per second on a regular cycle. Cycle can also be a unit for measuring usage of reciprocating machines, especially presses, in which cases "cycle" refers to one complete revolution of the mechanism being measured (i.e. the shaft of a reciprocating engine). Cycle per second The cycle per second was a once-common English name for the unit of frequency now known as the hertz (Hz). The plural form was typically used, often written cycles per second, cycles/second, c.p.s., c/s, ~, or, ambiguously, just cycles.
Mole (unit) in chemistry as a convenient way to express amounts of reactants and products of chemical reactions. For example, the chemical equation can be interpreted to mean that 2 mol dihydrogen (H) and 1 mol dioxygen (O) react to form 2 mol water (HO). The mole may also be used to represent the number of atoms, ions, or other entities in a given sample of a substance. The concentration of a solution is commonly expressed by its molarity, defined as the amount of dissolved substance per unit volume of solution, for which the unit typically used is moles per litre (mol/l).