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Properties of Nuclear Radiation

 

 

Objectives

• Know that there are three types of nuclear radiation.

• Know the main properties of the three types of nuclear radiation.

• Be able to compare the types of radiation in terms of ionising power and penetrating power.

 

 

 

 

Task 1 - Recap

Remind the person next to you:

• The three particles which make up an atom.

• How these particles are arranged.

• What is meant by an ion.

 

 

 

 

Task 2

Some elements have unstable nuclei.  This causes them to decay, releasing one of three types of radiation.  Your teacher will show you examples of several radioactive materials, each of which releases one (or more) types of radiation.

 

Watch the demonstrations to see how each type of radiation is affected as it passes through a range of materials.

 

SAFETY:

Radioactive substances can be incredibly harmful.  You MUST NOT touch any of the radioactive samples under any circumstances.  Your teacher will ask you to sit at least 2m back from the radioactive samples.  Follow your teacher's instructions carefully to avoid being harmed.

 

 

 

 

Task 3

Most of the properties of the different types of nuclear radiation can be deduced from basic knowledge of atomic structure, and the examples of the differing penetrating powers you have just seen.  Your teacher will give you a copy of the table below, and help you to fill in the two columns which have been marked with an asterisk.

 

Now, working with the person next to you, try to fill in your table.  Write all answers in pencil in case you make any mistakes!

 

Alpha

(α)

Beta

(β)

Gamma

(γ)
What is it?*  

 

 

    
Charge  

 

 

    

Relative size & mass

  

 

 

    
Relative speed  

 

 

    
Stopped by*  

 

 

    
Penetrating power  

 

 

    
Ionising power  

 

 

    

When you have finished, your teacher will go through the answers with you.

 

 

 

 

Task 4

Your teacher will give you a sheet with a copy of the information below.

An experiment is carried out with three radioactive sources. Different absorbing materials are put in front of each source, and the radiation passing through is measured. The results are shown below:

 

 

Radiation detected (counts per second)

Source

 no absorber thick cardboard 2cm of aluminium 2cm of lead
A 8 8 7 5
B 12 5 4 3
C 10 9 0 0

 

It is known that: one source emits beta particles; another source emits gamma rays; the third source gives out two types of radiation.

 

Try to decide which type(s) of radiation is given out by each source.

 

Source A emits ……………………………….

Source B emits ……………………………….

Source C emits ……………………………….

 

 

 

 

Homework/Extension

We find background radiation all around us.  Write a paragraph explaining what background radiation is, and where it comes from.  You should, in particular, include a section on Radon gas.