Y2_T4_LSN_4.5

• Science
• Middelbare school
• havo, vwo
• Leerjaar 2

Get ready

• Your Macbook (join the LessonUp)
• Your notebook.
• Your textbook.
• Pen & highlighter

Topic 4

Moving in the world

Plan for today

• Explanation T4.5 Moving particles
  
• (Make homework)
  
• LAB: Temperatures effects in reactions

4.5 Moving particles

Learning goals

I can....

• describe the three phases a substance can be in and list characteristics for each phase
• name the transition between the different phases
• identify phases and phase changes in a graph
• describe how the addition or removal of heat changes the movement of molecules and how this can cause phase changes
• describe the collision theory and how it affects reaction rate
• describe how the change in temperature affects the functionality of enzymes

Key words

• Diffusion
•  Solid
• Liquid
• Gas
• Collision theory
• Rate of a reaction
• Denaturation
• Optimum temperature

Diffusion

The spreading of molecules is called Diffusion

States of matter

The kinetic energy of molecules determines their speed of movement and how far away molecules move from each other.  This determines the phase the matter is in.

We have three phases:

• Solid
• Liquid
• Gas

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

A liquid has a fixed shape?

1. true
2. false

Phase transitions

Phase transition is a change of phase

Solid to liquid = Melting

Liquid to solid = Freezing

Liquid to gas = Evaporation

Gas to liquid = Condensation

Gas to solid = Deposition

Solid to gas = Sublimation

Phase transitions

During a phase change the 

temperature stays constant.

The temperature will not 

change until all molecules 

have transitioned.

A substance can change from solid to liquid. This is called a phase transition.
What is the name of this phase transition?

1. freezing
2. evaporation
3. melting
4. deposition

Collision theory

The movement of molecules is important for reacting.

Collision theory :

• In order for molecules to react they have to collide with enough force to reach the activation energy. 
• Temperature influences the rate of reaction because faster moving molecules have a higher chance of colliding with enough force to react.

Denaturation

If molecules collide too forcefully they can change shape. 

This is harmful for enzymes since they must fit perfectly into molecules in order to function.

Denaturation:  when enzymes change shape and don’t fit.

Optimum temperature

Optimum temperature:  where enzymes work fastest without denaturing

Homework

• Study the glossary of 4.5
  
• Complete the exercises of 4.5 (p.190 -195)

LAB: Temperatures effects in reactions

WARNING:  LAB = no warnings, misbehave --> 201

- Make a duo

- Get the worksheet from your teacher

- Grab your labjournal + Pen 

- Wait for your teacher to go to the lab