Study guide and assessment pages from a science textbook on properties of matter.

- 1. a. water
- 2. d. a mixture
- 3. b. suspension
- 4. b. flammability
- 5. c. wood
- 6. c. malleable
- 7. a. solid
- 8. d. baking a cake
- 9. a. reactivity
- 10. b. a chemical change
- 11. A pure substance has a fixed, uniform composition, so every sample contains the same proportion of elements or compounds, resulting in identical properties.
- 12. An element consists of only one type of atom and cannot be broken down into simpler substances by chemical means; a compound is made of two or more different elements chemically bonded in a fixed proportion.
- 13. A mixture of hydrogen and oxygen retains the individual properties of each gas and can vary in ratio; a compound containing hydrogen and oxygen (like water) has a fixed 2:1 ratio and exhibits entirely new properties.
- 14. Yes, it could still be heterogeneous if the grains differ in composition, color, mineral content, or other properties—even if they are the same size.
- 15. Filtration separates mixtures based on particle size; larger particles are trapped by the filter while smaller particles or liquids pass through.
- 16. Viscosity is classified as a physical property because it can be observed or measured without changing the substance’s chemical identity.
- 17. Pottery is brittle because it shatters when struck rather than deforming, which is characteristic of ceramic materials.
- 18. This is a physical property because drawing copper into wire involves changing its shape without altering its chemical composition.
- 19. Physical property: hardness; Chemical property: flammability.
- 20. Breaking down a compound into elements is a chemical change because it involves breaking chemical bonds and forming new substances with different properties.
- 21. Physical change: melting wax; Chemical change: burning wax produces carbon dioxide and water vapor.
- 22. Use physical properties first, such as color, density, or magnetism, because they allow identification without altering the material. Chemical properties involve reactions that may destroy or change the sample.