Inert

In English, to be inert is to be in a state of doing little or nothing.

Chemistry

In catalyst.

For example, covalent bond in the N₂ molecule.

Inert atmospheres of gases such as argon are routinely used in chemical reactions where air sensitive and water sensitive compounds are handled.

Number theory

In the branch of mathematics known as algebraic number theory, a prime ideal is said to be inert if it is still prime when considered in an extension field. Such a prime might have instead split as a product of other prime ideals, but by being inert it remains essentially unchanged.

Munitions

In the area of weapons, an inert munition is one in which all energetic material such as primer, fuze, and explosive or incendiary fill have been removed or rendered harmless. Inert munitions are used in military training and are collected in museums and by private individuals. See also military dummy.