changes of state and the particle model (topic 3)

Question 1

explain, in terms of the particles, why gases are easy to compress (2)

Answer 1

• (large) gaps between particles
• (so) easy to push particles closer (together)

Question 2

Answer 2

a random error

Question 3

use Figure 2 to determine the time taken for the stearic acid to change from a liquid
to a solid

Answer 3

740 (seconds)

Question 4

After 1200 seconds the temperature of the stearic acid continued to decrease.
Explain why

Answer 4

• stearic acid has a higher temperature than the surroundings
• temperature will decrease until stearic acid is the same as the room temperature