Question

this chemical formula is called an
element
atom
compound
substance

Explanation:

A compound is made up of two or more different - element atoms chemically bonded together. CO₂ is composed of one carbon atom and two oxygen atoms, so it is a compound. An element is a pure substance made of only one type of atom. An atom is the smallest unit of an element. A substance is a general term, but CO₂ is specifically a compound.

Answer:

C. compound