To determine which changes are physical changes, we need to identify changes that do not result in the formation of a new substance.
From the table:
- Change 1: Reacts with another substance? Yes; New substance formed? Yes (not a physical change)
- Change 2: Reacts with another substance? No; New substance formed? No (this is a physical change)
- Change 3: Reacts with another substance? Yes; New substance formed? Yes (not a physical change)
- Change 4: Reacts with another substance? No; New substance formed? No (this is a physical change)
Based on this analysis, the changes that are physical changes are Change 2 and Change 4.
So, the correct response is:
2 and 4.