Physical and chemical change

Question 1

What is physical change?

Answer 1

Physical change is when the physical properties of a substance change and no new substance is produced.

Question 2

Describe examples of physical change

Answer 2

Melting an ice cube and boiling water because it only involves a change in the physical state of the water with no change in the chemical composition.

Question 3

Describe the structure of solids

Answer 3

In solids, the particles are mostly arranged in a crystal lattice and are bonded tightly together, vibrating on the spot.

Question 4

Describe the structure of liquids

Answer 4

In liquids, the particles are more free flowing and are not arranged in any specific shape. They still are bonded together, but with more space in between each. They take the shape of the container.

Question 5

Describe the structure of gases

Answer 5

In gases, the particles have lots of space in between them because they are not bonded together and constantly move randomly. They have very little attraction to each other. The particles don’t interact with one another but just hit and bounce off of each other when they collide.

Question 6

Describe particle behaviour when they expand (heated)

Answer 6

When substances are heated, the vibration of the particles move faster and they begin to push each other apart. The particles begin to hit walls and weaken the attraction between each of them, resulting in the substance to expand.

Question 7

Describe particle behaviour when they contract (cooled)

Answer 7

When substances are cooled, the molecules slow down. This allows the particles to move closer together, so the substance contracts.