What is a molecule comprised of?

A molecule is specifically defined as two or more atoms that are chemically bonded together. These atoms can be of the same element, such as in the case of oxygen gas (O₂), where two oxygen atoms form a molecule, or they can be different elements, as seen in water (H₂O), where hydrogen and oxygen atoms are combined. The bonds that hold these atoms together can be ionic or covalent, but the key point is that a molecule consists of a distinct grouping of atoms formed through these chemical bonds.

This definition highlights the foundational aspect of molecules in chemistry, differentiating them from singular atoms or ionic compounds, which are not classified as molecules. Understanding this concept is crucial, as it lays the groundwork for many topics in chemistry, such as reactions, compounds, and the behavior of substances at the molecular level.