Question

What’s the difference between an atom, an element and a molecule (chemical compound)?

Answer 1

Atoms are the fundamental building blocks of the Universe. The definition of the atom is the least amount of matter that retains the chemical properties of the element.

A molecule is the result of the union of two or more atoms. The electrons found in the outermost shell of an atom (valence electrons) when shared between atoms, form a molecule.

A chemical element is a type of matter made up of atoms of the same class. In its simplest form, it has a certain number of protons in its nucleus, making it belong to a unique category classified by its atomic number, even though it can display different atomic masses.