Question

Which number remains unchanged during photosynthesis?

the number of carbon atoms
the number of carbon atoms

the number of water molecules
the number of water molecules

the number of glucose molecules
the number of glucose molecules

the number of carbon dioxide molecules
the number of carbon dioxide molecules

Answer 1

During photosynthesis, the number of carbon atoms remains unchanged in the overall process.

Photosynthesis converts carbon dioxide and water into glucose and oxygen using sunlight. While the number of carbon atoms changes in terms of their arrangement (as they are used to form glucose), the total number of carbon atoms in the reactants (carbon dioxide) and products (glucose and oxygen) in a balanced chemical equation remains consistent.

For reference, the overall equation for photosynthesis is:

\[ 6 \text{CO}_2 + 6 \text{H}_2\text{O} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6 \text{O}_2 \]

In this equation, while carbon is transformed and rearranged, the total number of carbon atoms on both sides does not change. So the **number of carbon atoms** is the answer.