There are only seven diatomic elements that default to this double bond. Five of them — hydrogen, nitrogen, fluorine, oxygen and chlorine — are gases at room temperature and normal pressure.

Fluorine and chlorine are gases. Bromine is one of only two liquid elements. Iodine is solid. They exist as diatomic molecules - they have two atoms in each molecule. As you go down the group the ...

Fluorine and chlorine are gases. Bromine is one of only two liquid elements. Iodine is solid. They exist as diatomic molecules - they have two atoms in each molecule. As you go down the group the ...