A scientist studies the formation of a new polymer. The table shows the numbers of each type of atom in the two functional groups that react to form one link.
| Carbon atoms | Hydrogen atoms | Oxygen atoms | Nitrogen atoms | |
|---|---|---|---|---|
| Before the link forms | 1 | 3 | 2 | 1 |
| In the new polymer link | 1 | 1 | 1 | 1 |
Use the information in the table to explain why the polymer forms by a condensation reaction.