Explanation:

- Gold:

- Gold is a metal that exists as separate atoms in its natural state.

- It is a monatomic element.

- Correct Answer: Gold is a monatomic unit.

- Sulphur:

- Typically found as S8, meaning 8 sulfur atoms form a molecule.

- Not monatomic, as it exists in polyatomic form in nature.

- Hydrogen:

- Exists primarily as H2 molecules in nature.

- Composed of two atoms, hence diatomic.

- Phosphorus:

- Commonly found as P4, a molecule of four atoms.

- Hence, it is not monatomic.