Propanal and propan-2-one are metamers.

Explanation

To determine whether propanal and propan-2-one are metamers, we need to analyze their structures and understand the concept of metamers.

### Step-by-Step Solution:

1. **Identify the Structures**:
- **Propanal**: This is an aldehyde with the molecular formula C3H6O. Its structure can be represented as:
\[
\text{CH}_3\text{CH}_2\text{CHO}
...