What term describes the bonds formed when two or more atoms join together?

The term that best describes the bonds formed when two or more atoms join together is "molecules." A molecule is defined as a group of two or more atoms that are chemically bonded together, which can occur through different types of bonding, such as covalent or ionic bonds. In this context, the term "molecules" emphasizes the end result of these atomic connections, which are stable entities made up of bonded atoms.

While covalent and ionic bonds refer to specific types of chemical bonds between atoms, they do not collectively describe the broader concept of what happens when atoms join. Covalent bonds involve the sharing of electrons between atoms, and ionic bonds involve the transfer of electrons, leading to the attraction between positively and negatively charged ions. "Isotopes" refers to variants of a chemical element that have the same number of protons but different numbers of neutrons, which is unrelated to the concept of atom bonding.

Thus, “molecules” accurately captures the idea of multiple atoms coming together to form a unified structure, making it the most appropriate term in this context.