How many single covalent bonds can halogens form?

1 Answer
Oct 11, 2016

A halogen can form one single covalent bond with an atom of a nonmetal, including itself.


Halogens, the elements in group 17/VIIA, have seven valence electrons. This is an unstable condition. They need one more electron to achieve a full valence shell with eight electrons, which is referred to as an octet. Covalent bonding, in which atoms share electrons from their valence shells, allows the halogens to form covalent bonds.

A chlorine atom is a halogen and it will covalently bond to another chlorine atom to form chlorine gas, #"Cl"_2"#.

Chlorine, as well as any other halogen, can also form covalent bonds with other atoms, such as hydrogen in the example below. In the case of hydrogen, which only has one valence electron, two electrons are needed for it to become stable. By covalent bonding between the hydrogen and chlorine atoms, the molecule hydrogen chloride is produced.