Chapter 6 - When Substances Change

Question 1

Physical change

Answer 1

• no new substance
• change in shape or size or state
• mixing with other substances
• reversible

Question 2

Expansion

Answer 2

When heated, particles move more frequently and expand. Decreases density.

Question 3

Contraction

Answer 3

When cooled, particles move less frequently and will contract. This increases density.

Question 4

Frequency

Answer 4

The warmer the substance, the higher the frequency and it will become gas. The cooler it is, the lower the frequency is and it becomes solid.

Question 5

Changes of state (gases to solids)

Answer 5

Gas to solid - Deposition
Solid to gas - sublimation

Question 6

Mixing

Answer 6

Formed when two or more substances are mixed together

Question 7

Diffusion

Answer 7

• solute particles diffuse evenly amongst the solvent
• when gases mix, they spread evenly
• agitation helps make diffusion faster (stirring, wind)