Record and classify each change
This is an assessed task. Watch each change carefully and record careful, scientific observations. The test for irreversible is always: has a new substance been made?
For each change your teacher demonstrates, complete one row. Write a detailed observation, classify it, say whether a new substance formed and how you know, and note one safety risk.
| Change | Observation | Reversible / irreversible | New substance? How I know | Safety risk |
|---|---|---|---|---|
| Melting butter | ||||
| Toasting bread | ||||
| Popping popcorn | ||||
| Ice melt then refreeze | ||||
| Burning paper |