Atoms are the smallest particle of matter. Genes are segments of DNA that code for a specific protein responsible for a trait in a living thing. Since genes take up space (have volume) and have mass, they are considered matter. Thus, genes are made of atoms.
Atoms are comprised of subatomic particles - protons, neutrons, and electrons. The positively charged protons and neutrally charged neutrons are located in the center nucleus of an atom. The negatively charged electrons are found moving around the nucleus in either electron clouds or orbitals.
Genes are segments of DNA (which stands for deoxyribose nucleic acid). Like all forms of matter, genes and DNA are made of atoms. DNA is shaped like a double helix (or a twisted ladder). The sides of this double helix is composed of alternating sugar (deoxyribose) and phosphate groups. The sugar of deoxyribose of made largely of the atoms carbon and hydrogen. In interior rungs of DNA's double helix is made of nucleotide base pairs. The atoms that make up these base pairs are mostly nitrogen, hydrogen and oxygen.