# Covalent compounds

## Key Questions

• Generally speaking, they do not - though there are exceptions.

In order for compounds to conduct electricity, there must be charged particles present - such as the case with ionic compounds which are composed of positively or negatively charged ions. There are also scenarios where unpaired electrons can also be free to conduct charge.

Acids, for example, can ionize in solution to produce ions, which are free to conduct electric current.

Certain polymers, with free electrons or multiple bonds can also conduct electric current.

Graphite also has a free electron which allows it to conduct electricity, even though it is composed of several covalent bonds.

So typically, even though we think of ionic compounds or metallic compounds able to conduct electric current, there are some instances where covalently bonded molecular compounds can conduct electricity as well.

• Covalent compounds, also known as molecular compounds, are formed from the sharing of valence electrons.

These electrons are shared to fill the outermost s and p orbitals, thus stabilizing each atom in the compound.

If you examine the word, covalent, it means with valence electrons.

These compounds are formed when two non metals combine chemically.

Some common examples are water,${H}_{2} O$, carbon dioxide, $C {O}_{2}$', and hydrogen gas which is diatomic, ${H}_{2}$.

Covalent compounds can be subdivided into polar and no polar compounds. In water, a polar molecule, the hydrogen electrons are not shared equally with the oxygen atoms; this results in a polar bond. Oxygen due to it's greater electro negativity "pulls" the electrons closer to its nucleus.

In hydrogen gas, the electronegativity is the same for both hydrogen atoms, so that there is equal sharing, making this bond a nonpolar covalent bond.