The seven elements that occur as diatomic molecules under standard conditions are:

* Hydrogen (H₂)

* Nitrogen (N₂)

* Oxygen (O₂)

* Fluorine (F₂)

* Chlorine (Cl₂)

* Bromine (Br₂)

* Iodine (I₂)

These elements are more stable as diatomic molecules due to the strong covalent bonds they form with themselves. These bonds are formed by sharing electrons between two atoms of the same element, resulting in a more stable electron configuration.

It's important to remember that these elements are not the *only* elements that can form diatomic molecules, just the ones that are commonly found as diatomic molecules in nature.