Question
Decide whether a physical or chemical change has occurred and give evidence for your decision. The first one has been done for you to use as an example.
In a fireworks show, the fireworks explode giving off heat and light.
In a fireworks show, the fireworks explode giving off heat and light.
Answers
GPT-4o mini
In the fireworks show example, a **chemical change** has occurred. The evidence for this decision includes:
1. **Formation of new substances**: When fireworks explode, they undergo a chemical reaction that produces gases, metals, and other compounds that were not present before the reaction.
2. **Heat and light production**: The explosion releases heat and light energy, which are typical indicators of chemical changes, as they often involve the breaking and forming of bonds between atoms.
3. **Irreversibility**: Once the fireworks have exploded, the reaction cannot be reversed to return to the original materials (e.g., gunpowder, metal salts).
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Here's another example for you:
**Rusting of Iron**: When iron is exposed to oxygen and moisture over time, it forms rust (iron oxide).
- **Type of change**: Chemical change.
- **Evidence**:
1. **Formation of a new substance**: Rust is a different compound than the original iron.
2. **Color change**: The iron changes from metallic gray to reddish-brown rust, indicating a chemical transformation.
3. **Irreversibility**: Once iron has rusted, it cannot be converted back to pure iron without a chemical process.
1. **Formation of new substances**: When fireworks explode, they undergo a chemical reaction that produces gases, metals, and other compounds that were not present before the reaction.
2. **Heat and light production**: The explosion releases heat and light energy, which are typical indicators of chemical changes, as they often involve the breaking and forming of bonds between atoms.
3. **Irreversibility**: Once the fireworks have exploded, the reaction cannot be reversed to return to the original materials (e.g., gunpowder, metal salts).
---
Here's another example for you:
**Rusting of Iron**: When iron is exposed to oxygen and moisture over time, it forms rust (iron oxide).
- **Type of change**: Chemical change.
- **Evidence**:
1. **Formation of a new substance**: Rust is a different compound than the original iron.
2. **Color change**: The iron changes from metallic gray to reddish-brown rust, indicating a chemical transformation.
3. **Irreversibility**: Once iron has rusted, it cannot be converted back to pure iron without a chemical process.