Physical and Chemical Changes interactive worksheet for 7 | Live ... - Free Printable

The image presents a grid of 20 different processes or actions, each illustrated with an image and a brief description. The task likely involves classifying these processes as either physical changes or chemical changes.

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🔬 Understanding the Concepts:

- Physical Change: A change in which the substance's form or state changes, but its chemical composition remains the same. No new substances are formed.
- Examples: cutting, melting, freezing, boiling, dissolving, crushing.

- Chemical Change: A change where new substances are formed due to a chemical reaction. The original substances are transformed into different ones.
- Examples: burning, rusting, cooking, digesting, rotting.

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✔ Let's classify each process:

| Image | Process | Type of Change | Reason |
|------|--------|----------------|-------|
| 1 | Cutting an apple | Physical | Only shape changes; no new substances. |
| 2 | Baking a cookie | Chemical | Ingredients react (e.g., proteins denature, Maillard reaction). |
| 3 | Lighting a match | Chemical | Combustion occurs (wood + oxygen → CO₂ + H₂O + heat). |
| 4 | Melting ice | Physical | Solid to liquid; water remains H₂O. |
| 5 | Roasting a marshmallow | Chemical | Sugar caramelizes, browning occurs (Maillard reaction). |
| 6 | Freezing water | Physical | Liquid to solid; still H₂O. |
| 7 | Burning a candle | Chemical | Wax combusts, producing CO₂ and H₂O. |
| 8 | Dissolving sugar | Physical | Sugar molecules disperse in water, but remain sugar. |
| 9 | Ripping paper | Physical | Paper is torn, but no chemical change. |
| 10 | Slicing bread | Physical | Shape changed, not chemically altered. |
| 11 | Boiling water | Physical | Phase change from liquid to gas. |
| 12 | Crushing a can | Physical | Shape changes, material stays the same. |
| 13 | Breaking a mirror | Physical | Glass shatters, but composition unchanged. |
| 14 | A decaying leaf | Chemical | Decomposition by microbes; organic matter breaks down. |
| 15 | Frying an egg | Chemical | Proteins denature and coagulate (irreversible). |
| 16 | Mixing vinegar and baking soda | Chemical | Produces CO₂ gas (fizzing), a new substance. |
| 17 | A rusting bike | Chemical | Iron reacts with oxygen to form iron oxide (rust). |
| 18 | Burning wood | Chemical | Combustion produces ash, CO₂, and other gases. |
| 19 | Cutting grass | Physical | Grass is cut, but no chemical change. |
| 20 | Digesting food | Chemical | Enzymes break down food into simpler molecules (e.g., starch → glucose). |

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📊 Summary Table:

| Physical Changes | Chemical Changes |
|------------------|------------------|
| Cutting an apple | Baking a cookie |
| Melting ice | Lighting a match |
| Freezing water | Roasting a marshmallow |
| Dissolving sugar | Burning a candle |
| Ripping paper | Boiling water |
| Slicing bread | Crushing a can |
| Breaking a mirror | A decaying leaf |
| Cutting grass | Frying an egg |
| | Mixing vinegar and baking soda |
| | A rusting bike |
| | Burning wood |
| | Digesting food |

> ⚠️ Note: Boiling water is sometimes debated, but it's physical because it’s just phase change (no new substance).

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✔ Final Answer:

You should categorize the 20 processes into two groups:
- 10 Physical Changes
- 10 Chemical Changes

This classification helps students understand the difference between changes in form vs. changes in substance.

Let me know if you'd like this formatted as a worksheet or chart!