How can oxygen make two single bonds?

1 Answer

It has a valency of 2.


Basically, oxygen has six electrons in its outer (valence) electron shell, which means that it needs two electrons to complete its octet #-># oxygen is said to have a valency of two.

A single bond is comprised of two electrons, usually each from different atoms. In the case of oxygen, it has six valence electrons, so is able to form two single bonds, leaving four nonbonding electrons.

An example of this is in water, #"H"_2"O"#.

There are two hydrogen atoms, which both have a valency of one, bonded to the single oxygen atom, which has a valency of two. One of the valence electrons in the oxygen forms a covalent bond with one of the hydrogens and its electron, and another oxygen valence electron forms a covalent bond with the other hydrogen, forming water.