Final answer:
The chemical formula that represents both an element and a molecule is diatomic elements such as hydrogen (H₂), oxygen (O₂), and nitrogen (N₂), which consist of two atoms of the same element bonded together.
Step-by-step explanation:
The chemical formula that represents both an element and a molecule is the formula for a diatomic element. Diatomic molecules are molecules composed of only two atoms, of the same or different chemical elements. The prefix 'di-' in 'diatomic' refers to the two atoms.
Examples of diatomic elements include hydrogen (H₂), oxygen (O₂), and nitrogen (N₂). These molecules are a collection of two atoms that are chemically bonded together. For instance, diatomic oxygen (O₂) is both the elemental form of oxygen as found in nature and a molecule because it consists of two oxygen atoms bonded together.