1. P2 Concept 2
The 3 types of ionising radiation
recall the three types of ionising radiation emitted by
radioactive materials
• distinguish between alpha, beta and gamma radiation by
their properties – penetration & ionising ability
•
Can radiation be stopped?

2. Notes…A radiation is ionising if it has
enough energy remove electrons from
atoms, producing ions.
The ionising ability of the 3 types of radiation
can be seen using a spark counter. When atoms
in the air is ionised, sparks will jump across.

3. If ionisation happens to atoms in
individual cells, the ions produced can
damage DNA. This mutation can lead to
cancer.

4. Demonstration
Watch carefully and note down your
observations.

5. Demonstration
Watch the demo and think about these questions:
• Which radiation is easily stopped?
• Which radiation is the most ionising?
Radiation
alpha
beta
gamma
Source
Range in air
Stopped by
Ionisation

6. Recap

7. Check learning - Explain
Look at the information you have recorded.
1. Which radiation is most easily stopped?
2. Which radiation is most ionising?
3. Suggest how your answers might be related.
Applying ideas
Americium-241 emits alpha particles. The fact that
it is radioactive would not help doctors detect that it
was in a patient’s body. Explain why.

8. alpha
beta
gamma

9. paper
alpha
beta
gamma

10. alpha
beta
gamma
aluminium

11. paper
alpha
beta
gamma
aluminium
lead

12. 4
2
6
1
6
3
2
9
5
6 Copy the table into the
back of your book
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Starter Designed by Eugene Brunet; Adapted for PowerPoint by A. Camburn, St George School
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