What are the SEVEN DiAtomic molecules? List them and explain why there are DiAtomic and NOT MonAtomic molecules.

See explanation

Explanation:

The seven elements that form diatomic molecules are:

Hydrogen (H) => H₂

Nitrogen (N) => N₂

Oxygen (O) => O₂        

Fluorine (F) => F₂

Chlorine (Cl) => Cl₂  

Bromine (Br) => Br₂

Iodine (I) => I₂    

How to remember the '7' diatomics => look at periodic table and draw a horizontal line starting at Nitrogen (N) through Fluorine (F), then a vertical line from Fluorine (F) through Astatine (As). The lines drawn make the number '7'. One only need to remember Hydrogen (H) also belongs to the set of elements forming diatomic molecules.