3.3 Phase changes

• Natuurkunde / Scheikunde
• Middelbare school
• havo, vwo
• Leerjaar 2

Chapter 3.3 Phase changes

Recap of the last class

What did we do/talk about the last time? 

Last time we talked about...

Temperature

How are we able to measure the temperature?

And do we remember which unit(s) we use for temperature?

How many Kelvin is 75 degrees Celsius

1. -198 Kelvin
2. 0,27 Kelvin
3. 3,64 Kelvin
4. 348 Kelvin

150 degrees Celsius is .....

1. 288 Kelvin
2. 423 Kelvin
3. 4095 Kelvin
4. 18,2 Kelvin

Learning objectives

You can name the six phase changes that substances can undergo

You can describe how the phase transitions of water play a key role in all kinds of weather phenomena

You can use the particle model to explain why temperature plays a key role in melting and evaporation

Please take notes in your notebook! 

Phase transitions in the particle model

We are going to look at the particle model again. This time we will look at how to movement of the molecules change depending on the temperature.

CLICK HERE

Increase in temperature 

Increase in (kinetic) energy and space between them 

Solid

- Fixed shape (crystal)

- Molecules are vibrating

- Not a lot of kinetic energy

         (Low temperature)

Liquid

- No fixed shape, Volume fixed

- More space between molecules and they shake a lot more (more kinetic energy)

- Medium kinetic energy

           (medium temperature)

Gas

- No fixed shape, no fixed volume

- Distance between molecules is big

- Velocity of molecules is high, Kinetic energy is high

which phase does not have a fixed volume?

1. solid
2. liquid
3. gas
4. magma

When it is cold outside and you breathe out, a cloud of mist appears.

Take a look at the photo and complete the sentences correctly.

The point on the photo where there is a cloud of mist is labelled 

A

B

l

Which phase transition is it when gas becomes a liquid?

1. sublimation
2. condensation
3. deposition
4. evaporation

Josh breathes on the window: the window fogs over. What is the term for the phase transition: that creates a moist spot on the window?

1. condensation
2. sublimation
3. evaporation
4. solidification

Which phase transition is it when gas becomes a solid?

1. sublimation
2. evaporation
3. condensation
4. deposition

What is sublimation?

1. When a solid turns into a gas
2. When a gas turns into a solid
3. When a gas turns into a liquid

How do we call this phase transition?

1. Sublimation
2. Evaporation
3. Melting
4. Freezing

What is phase
transition 3 called?

1. evaporation
2. solidification
3. sublimation
4. deposition

Heat is required at the phase transition

1. deposition
2. sublimation
3. boiling
4. evaporation

Phase transitions 

As we know, weather can change suddenly

A day can start sunny, but end up with a thunderstorm

Phase transitions 

And so do substances!

When water freezes or melts it is known as a phase transition 

A substance transitions depending on the temperature

Phase transitions 

There are six phase transitions 

We will walk through these transitions with examples and pictures

Freezing/solidification liquid->solid

When water freezes it turns into ice

The term solidifying is also used, but for things that turn solid at temperatures above 0 degrees Celsius like candle wax

Melting solid->liquid

When the temperature rises, the solid ice will turn into a liquid again

Evaporation liquid->gas

Over time, when it is warm enough, water can turn into invisable water vapour

Condensation gas->liquid

But when warm air cools down and meets a cold object, water vapour condenses out and turns water vapour into visable water

Deposition gas->solid

When the temperature drops below 0 degree Celsius, water vapour turns into solid ice

Sublimation solid->gas

Snow will slowely get thinner, this is because ice turns into water vapour when the air is cold and dry

But there are substances that can turn from a solid to a gas a lot faster

Both processes are called sublimation

https://www.youtube.com/watch?v=8Gj8dr6AsYg

Phase transitions

Solid to liquid = Melting

Liquid to solid = Freezing

Liquid to gas = Evaporation

Gas to liquid = Condensation

Gas to solid = Deposition

Solid to gas = Sublimation

What phase is water in to each of the following weather types?

Liquid

Gas

Solid

Rain

Snow

Hail

Fog

Frost

There are 6 phase. Put the corect description next to each of six phase transitions

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 / freezing

melting

evaporation

condensation

deposition

sublimation

Task 1

Start up your LessonUp

Do the test about particles and phase transitions.

You can only use your notes and the information in the powerpoint. So book is closed.

Task 2

Let's Play a Game!!

You'll work and play in groups of 4 (or 3)

Create the phase transition board game.

Play the game.

What did we learn today?

In today's lesson we talked about the different phase transitions 

What did we learn today?

And how temperature changes the way the molecules move in the particle model

Please try the following:

Make the following questions: 1 to 4 & 6 to 8.