What is a diatomic molecule?

A diatomic molecule is defined as a molecule composed of two atoms. The correct answer describes a diatomic molecule accurately as a molecule consisting of two identical nonmetal atoms, such as O2 (oxygen) or N2 (nitrogen). These particular diatomic molecules are stable and exist naturally as two atoms bonded together, and they play crucial roles in various chemical reactions and in the atmosphere.

Diatomic molecules can also include cases where the two atoms are different, such as in hydrogen chloride (HCl), but when referring specifically to identical nonmetal atoms, it accurately captures some common examples of diatomic molecules. The term "diatomic" itself is derived from the Greek words "di," meaning two, and "atomos," meaning indivisible, emphasizing the two-atom nature of these molecules.

The other options do not align with the definition of a diatomic molecule. For instance, a molecule made of two metallic atoms does not capture the essence of being nonmetal, nor does the description of a compound with three or more elements fit the diatomic definition. Additionally, referring to a pure substance made up of two or more chemically combined elements describes a broader category that includes compounds, rather than focusing specifically on the two-atom aspect of di