<span>An ionized atom has a number of protons that is unequal to the number of electrons. - I took the Penn exam, 100% sure!</span>
When a single compound breaks down into two or more compounds or elements in a chemical reaction then it is known as decomposition reaction.
The chemical symbol for sodium carbonate is
.
The decomposition of sodium carbonate is:

The decomposition of sodium bicarbonate,
will result in the formation of sodium oxide,
and carbon dioxide,
.
Hence, carbon dioxide,
will produce with sodium oxide,
on decomposition of
.
The answer to your question is
D: Unshared Pair
Hope this helps you :))))