The seven elements that exist as diatomic molecules under standard conditions (room temperature and pressure) are:

* Hydrogen (H₂)

* Nitrogen (N₂)

* Oxygen (O₂)

* Fluorine (F₂)

* Chlorine (Cl₂)

* Bromine (Br₂)

* Iodine (I₂)

These elements exist as diatomic molecules because their atoms are more stable when they share electrons to form a covalent bond. This results in a more stable electron configuration.