Question

write p for physical change or c for chemical change.

1. ___ a paper getting crumpled
2. ___ water condensing into clouds
3. ___ rusting on a car

write c for compound or m for mixture to complete the sentences.

1. _ a _ is formed or separated by chemical processes.
2. _ the materials in a _ keep most or all of their properties.
3. _ a _ is formed or separated by physical processes.

Explanation:

• 20: A paper getting crumpled is a physical change as only the shape of the paper changes and no new substance is formed.
• 21: Water condensing into clouds is a physical change. It is a change of state (from gas - water vapor to liquid - water droplets in clouds) and no new chemical substance is created.
• 22: Rusting on a car is a chemical change. Rust (iron oxide) is a new substance formed when iron reacts with oxygen and moisture.
• 23: A compound is formed or separated by chemical processes. Compounds are substances composed of two or more elements chemically combined.
• 24: The materials in a mixture keep most or all of their properties. In a mixture, the components retain their individual chemical properties.
• 25: A mixture is formed or separated by physical processes. For example, sand and water in a mixture can be separated by filtration (a physical method).

Answer:

1. P
2. P
3. C
4. C
5. M
6. M