What term describes the smallest particle of matter?

The term that describes the smallest particle of matter is "atom." An atom is the fundamental building block of all matter and is composed of protons, neutrons, and electrons. It represents the smallest unit that retains the unique properties of an element. Atoms can combine to form molecules but, on their own, they are the most basic unit of chemical elements.

Molecules, on the other hand, are formed when two or more atoms bond together. This means that while they are composed of atoms, they cannot be considered the smallest particle of matter.

Compounds consist of two or more different types of atoms bonded together in a fixed ratio, meaning they are made up of multiple atoms and therefore can’t be the smallest unit of matter.

Cells are the basic structural and functional units of living organisms, comprising many molecules and atoms, which makes them much larger than individual atoms.

Thus, atoms are indeed the smallest particles of matter that retain elemental properties, distinguishing them from larger structures.