An atom is what makes up chemical formulae. Just look at the Periodic Table -- those are your chemical formulae for atoms. Can be from H to Uuo.
The chemical formula for potassium iodide is KI. It consists of one potassium atom (K) and one iodide atom (I).
The diatomic chemical formula of chlorine is Cl2.
There is one atom of that element in the molecule.
The chemical formula of potassium phosphide is K3P. It is composed of one potassium atom (K) and one phosphorus atom (P) combined in a 1:1 ratio.
The chemical formula for pyrite is FeS2, which means it consists of one iron (Fe) atom and two sulfur (S) atoms.
The chemical formula for one carbon atom combined with one oxygen atom is CO.
The central atom in the molecule with the chemical formula ClO2 has a hybridization of sp2.
The chemical formula for sulfur monochloride is SCl. It is composed of one sulfur atom and one chlorine atom.
Each chemical element has a standardized chemical symbol, not a formula.
The subscript in a chemical formula represents the amount of that atom in that compound's formula.
H2O. It is the formula of water.
The chemical formula for silicon sulfide is SiS. It is composed of one silicon atom bonded to one sulfur atom.
The chemical formula for potassium iodide is KI. It consists of one potassium atom (K) and one iodide atom (I).
NH3
H
Cl.
The chemical formula for carbon monoxide is CO, indicating one carbon atom and one oxygen atom in the molecule.