I apologize for any confusion caused by my previous response. Hydrogen is indeed made up of individual hydrogen atoms, not two hydrogen atoms. A single hydrogen atom consists of one proton in the nucleus and one electron orbiting around it. So when people refer to hydrogen, they are typically referring to a single hydrogen atom.
However, hydrogen can also exist in a diatomic form, where two hydrogen atoms combine to form a hydrogen molecule (H2). In a hydrogen molecule, the two hydrogen atoms are bonded together by a covalent bond. This means that the two atoms share electrons, resulting in a more stable configuration compared to separate hydrogen atoms.
The formation of a hydrogen molecule occurs due to the nature of the chemical bonding between atoms. Hydrogen has a strong tendency to fill its outermost electron shell, which consists of two electrons. By sharing electrons, each hydrogen atom can achieve a stable electron configuration with a filled shell, resembling the electron configuration of helium.
The term "molecule" is generally used to describe a stable, electrically neutral group of atoms held together by chemical bonds. In the case of hydrogen, when two hydrogen atoms are bonded together, they form a hydrogen molecule (H2), which is the most common and stable form of hydrogen under normal conditions.
So, to clarify, when people refer to hydrogen as a molecule, they are specifically referring to the diatomic form (H2) where two hydrogen atoms are chemically bonded. When they refer to hydrogen as an atom, they are referring to a single hydrogen atom (H).