1. Date Lesson 3: Refraction Connector: (Level 4)
Explain that light bending at the surface of glass or water can deceive us
Look at the set up of a straw in a beaker, draw what you see
Lesson Outcomes
How I did
Targets
Task 1:
Explain that light is refracted towards the normal as it enters a denser transparent material and away when it leaves . Level 5
Task 2:
Draw a ray diagram to describe what happens when a ray of light is refracted on entering and leaving a glass block. Level 6
Task 3:
Apply knowledge of refraction to everyday examples. Level 7
Set up a straw and beaker of water in front of pupils

2. BIG picture What skills will you be developing this lesson? ICT
Numeracy
Literacy
Team work
Self management
Creative thinking
Independent enquiry
Participation
Reflection

3. HOW SCIENCE WORKS
How is this lesson relevant to every day life? (WRL/CIT)

4. This causes the light to bend or refract.
Bending light
The speed of light waves depends on the material they are travelling through.
air = fastest
glass = slower
diamond = slowest
If light waves enter a different material (e.g. travel from glass into air) the speed changes.
This causes the light to bend or refract.
glass
air

7. New Information for Task 1

8. Task 1 (Level 5) Task 1: Label diagram using key words
Explain why light gets refracted
Keywords for Task 1:
angle of incidence
Angle of refraction
Normal

9. Task 1: Answers
Light gets refracted as it slows down, light travels fastest through air, and slower through glass. The change is speed causes the light to bend.

10. How can I improve on task 1?
Task 1: Review
Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
How I did
Targets
Task 1:
Level 5
Met?
Partly met?
Not met?
How can I improve on task 1?

11. New Information for Task 2

13. incident light ray refracted light ray normal angle measured here
semi-circular glass block
refracted light ray
angle measured here
normal

14. Task 2 (Level 6)
Carefully mark the angles on the sheet of paper, making sure that they are lined up with the centre of the flat side of the glass block.
Shine the light accurately along the first line so that the light ray hits the centre of the glass block.
Mark the line of light that comes out of the curved side of the glass block accurately, using a ruler,
Measure the angle between the straight through line and each light ray.
Record results
Draw a grph
Keywords for Task 2:
refraction
Light
Bends
Angle
ray

15. Task 2: Answers
Angle of incidenceº
Angle of refractionº

16. How can I improve on task 2?
Task 2: Review
Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
How I did
Targets
Task 2:
Level 6
Met?
Partly met?
Not met?
How can I improve on task 2?

17. New Information for Task 3

18. Task 3 Cut a piece of graph paper in two.
2 Put one of the pieces of graph paper under an empty beaker.
3 Place the second piece of graph paper next to the beaker.
4 Look from above. You will notice that the squares on the graph paper look about the same size as each other.
5 Now half fill the beaker with water and look again.
6 Draw what you see. Pay particular attention to the size of the squares on the two pieces of graph paper.
7 Now slowly lift the piece of graph paper that is next to the beaker until the sizes of the squares look the same (you need to keep this piece of graph paper next to the beaker).
8 Measure the depth of the water and the distance from the surface of the water to the lifted piece of graph paper.
9 Try steps 5–8 again with the beaker full of water.

19. Task 3: (Level 7)
Task 3:
Use the data to explain which material caused the most refraction
Task 3: Extension
Keywords for Task 3:
refraction
incidence
angle

20. Task 3: Answers

21. How can I improve on task 3?
Task 3: Review
Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
How I did
Targets
Task 3:
Level 7
Met?
Partly met?
Not met?
How can I improve on task 3?

22. Homework Homework task: Due date: Criteria for level 5:

23. Review of lesson This is the answer what was the question? Incidence
Refraction
Ray
Light
Glass
diamond