Final answer:
Atoms are considered inert when they do not participate in chemical bonding. Inert atoms do not form ions or participate in the formation of covalent bonds. Elements such as helium and larger atoms with eight electrons in their valence shell are stable and unlikely to participate in chemical reactions.
Step-by-step explanation:
Atoms are considered inert when they do not participate in chemical bonding. As mentioned earlier, when an atom does not contain equal numbers of protons and electrons, it becomes an ion. Inert atoms do not form ions or participate in the formation of covalent bonds. For example, elements such as helium and larger atoms with eight electrons in their valence shell are stable and unlikely to participate in chemical reactions.