What is the smallest unit of matter that has characteristic properties of its element? atom molecule gas compound

An ATOM is the smallest unit of matter that has characteristic properties of its element

Explanation:

An atom a major part of the matter. (Everything in the world (except energy) is made of a material, and, so, everything in the universe is composed of atoms.

An atom itself is made up of three small kinds of particles called subatomic particles: protons, neutrons, and electrons. The protons and the neutrons proceed up the center of the atom called the nucleus and the electrons travel around above the nucleus in a little cloud. The electrons display a negative charge and the protons bear a positive charge.

answer carbon and three oxygen atoms;