Changes Of State And Particel Model

Question 1

What is the definition of density? State the relevant equation with units.

Answer 1

The mass per unit volume of a material.

Density (p) = mass (m) / volume (v)
Kg/m3 Kg M3

Question 2

State the different states of matter (least to most) in order of density of atoms

Answer 2

Gas
Liquid
Solid

Question 3

Describe the particle arrangement of a solid

Answer 3

Tightly packed in a regular arrangement. Particles can only vibrate on the spot.

Question 4

Describe the particle arrangement of a liquid

Answer 4

Close together, with an irregular arrangement. Can flow over each other.

Question 5

Describe the particle arrangement of a gas

Answer 5

Separated, no regular arrangement. Particles move freely.

Question 6

What is always kept the same when a substance undergoes a change of state?

Answer 6

Mass

Question 7

How does a change of state differ from a chemical change?

Answer 7

Ina change of state, material can return to having its precious properties of the change is reversed.

Question 8

What is sublimation?

Answer 8

When a solid changes into a gas without changing into a liquid first.

Question 9

What is evaporation?

Answer 9

When a liquid changes into a gas

Question 10

What is the opposite of evaporation?

Answer 10

Condensation; gas changes to a liquid

Question 11

When water boils in an open pan, why does the mass of the pan of water appear to decrease?

Answer 11

Some water will evaporate into water vapour. It leaves the pan so the mass decreases. The mass of the whole system remains constant.

Question 12

Explain the process included when the bathroom mirror heats up

Answer 12

Hot water evaporates to water vapour.
Water vapour land on the cool mirror.
Vapour condensates and returns to liquid on mirrors surface.