What term is used for elements that commonly form units of multiple atoms bonded together?

The term "polyatomic element" refers to elements that exist as molecules composed of multiple atoms bonded together. For example, phosphorus can exist as P4, which is a molecule consisting of four phosphorus atoms. These atoms are covalently bonded, resulting in a stable unit that behaves as a single entity in chemical reactions and interactions.

In contrast, monatomic elements consist of single, unbonded atoms, such as noble gases like helium or neon. Diatomic elements, like oxygen (O2) or nitrogen (N2), exist as pairs of atoms. The term "substance" is more generic and can refer to any form of matter, including elements or compounds, but it does not specifically describe a grouping based on the number of constituent atoms.

Thus, "polyatomic element" accurately captures the concept of elements that commonly exist as groups of multiple atoms bonded together.