Which of the following elements is a diatomic molecule in its natural state?

A diatomic molecule is one that consists of two atoms, which can be of the same or different elements. In their natural state, some elements exist as diatomic molecules, meaning that in their gaseous form, they naturally pair up with another atom of the same element.

Nitrogen is a prime example of this. It naturally occurs in the atmosphere as N2, meaning two nitrogen atoms bond together to form a stable molecule. This is characteristic of several other nonmetals, notably hydrogen (H2), oxygen (O2), fluorine (F2), chlorine (Cl2), bromine (Br2), and iodine (I2). They cannot exist in a singular, unbonded atomic form under standard conditions because diatomic forms provide greater stability.

Sodium and silver are metals and typically exist as individual atoms in their elemental states rather than forming diatomic molecules. Argon is a noble gas, and noble gases generally exist as single atoms due to their complete valence electron shell, making diatomic bonding unnecessary and unlikely.

Thus, nitrogen is the correct answer since it naturally forms a diatomic molecule (N2) in the environment.