In science, en can refer to the prefix en- (Greek) meaning "in" or "within" or or alternatively "to go into" or "cause to be", depending, as in en-ergon (work), en-tropy (entropy), or en-ergy (energy); or the abbreviation EN (technical) maning exponent E to the power of some number N.
Exponent
The term EN is sometimes found as an old-fashioned short notation scheme for exponent E to the power of some number N, which is written formulaically as follows:
This notation scheme is useful in expressing shorthand notation for numbers of atoms in a human molecule which can reach upwards E27, depending on atom, such as hydrogen or oxygen. Hence, for instance, the notation:
ZnE22