Particle model of matter

Question 1

Why is it incorrect to say iron is heavier than wood?

Answer 1

Depends how much iron and wood you have. Iron is denser than wood.

Question 2

Are changes of state physical or chemical?

Answer 2

Physical changes, can be reversed so material recovers its original properties, no new products form. Doesn’t happen in chemical changes, can’t be easily changed back.

Question 3

What will happen to the mass of a substance after it is melted?

Answer 3

Stay the same, mass is conserved when state changes.

Question 4

Describe how to determine the volume of irregular objects (e.g. brass key).

Answer 4

Drop object in water, measure amount of water displaced, that is the volume.