3.3 Phase Change

• Natuurkunde
• Middelbare school
• vwo
• Leerjaar 2

Plan for today

1. Testing your knowledge

2. Phase changes/transitions

3. Working on the exercises

Which one of these is NOT
a phase?

1. Water
2. Gas
3. Liquid
4. Solid

True or false:
Water vapour is invisible.

1. True
2. False

True or false:
A thermometer works because
ethanol shrinks as the temperature increases

1. True
2. False

If we are heating up a block of ice, from what temperature will it start to melt?

1. -10 °C
2. 0 °C
3. 10 °C
4. 1 °C

In which phase has molecules the less freedom of movement?

1. Gas phase
2. Solid phase
3. Liquid phase

What is the name for the attractive force between molecules of same substance?

1. adhesion
2. cohesion

In the image you can see a representation of the particle model of a certain substance.
At what stage is this substance?

1. The gas phase
2. The solid phase
3. The liquid phase

In the image you can see a representation of the particle model of a certain substance.
At what stage is this substance?

1. The solid phase
2. The liquid phase
3. The gas phase

Learning objectives

1. You can name the 6 phase changes.

2. You can describe the phase changes in the particle model.

3. You can name and recognize real-life examples of the phase changes

Phase transitions

Temperature and movement

The higher the temperature the faster the particles move. 

If they move faste enough then they can escape. 

Below, you can see this happening when water starts evaporating.

Boiling

The process by which evaporation occurs anywhere in the liquid.

Water is special

Water is smallest at 4 degrees Celsius. 

This is due to its crystal structure. 

Crystal structure of water

Which phase transition you see in the picture?

1. Evaporation
2. Melting
3. Condensation
4. Freezing / Solidification

Fog occurs when a lot of water droplets are suspended in the air. After a clear day, fog suddenly appears
What can you say about the temperature?

1. It has turned colder
2. The temperature has stayed the same
3. It has turned warmer

Water expands when it is heated
Why?

1. The distances between the molecules become greater
2. More water molecules are being added
3. the distances between the molecules become smaller

Which phase transition belongs to this sentence:
The rice is cooked completely dry.

1. Evaporation
2. Melting
3. Condensation
4. Freezing / solidification

7) Match correct descriptions with each phase transition.

from gas to liquid

from solid to liquid

from solid to gas

from liquid to solid

from liquid to gas

from gas to solid

solidification

melting

evaporation

condensation

deposition

sublimation

Homework

Chapter 3 section 3

Assignments: 1 till 7