How do we determine the covalency of various molecules?

2 Answers
May 20, 2017

You will have to give some context to your question........


A better term than #"covalency"# might be #"molecularity"#. Molecular species TEND to have reduced melting points and boiling points with respect to non-molecular species. Non molecular species, which include sodium chloride, and graphite, and diamond, thus have much HIGHER melting points than methane or ethane, or water, which are composed of discrete molecules.

May 23, 2017

Draw the Lewis structure and count the number of shared electron pairs.


Covalency is the number of bonds an atom forms within a molecule.

To determine the covalency, you draw the Lewis structure of the molecule and count the number of shared electron pairs.

Here are some examples.

Covalency = 1


Hydrogen and chlorine can each form one bond. can form one bond.

Covalency = 2

Oxygen atoms can form two bonds.

Covalency = 3

A nitrogen atom can form three bonds.

Covalency = 4

A carbon atom can form 4 bonds.

Covalency >4

Many atoms with atomic number greater than 14 can form 5 or 6 bonds.