26.8 - Experiments Involving Radioactivity

Question 1

List the safety precautions when doing an experiment with a radioactive source:

Answer 1

• A sealed source must always be used
• The source must be kept in a lead box in a separate labelled room
• Protective gloves should be worn
• Always handle the source with tongs
• Keep as far away from the source as possible
• Minimise exposure time
• Lock the source away as soon as the experiment is finished

Question 2

How can the A = Aoe^-λt equation be manipulated into a straight line equation?

Answer 2

A = Aoe^-λt
lnA = lnAo - λt
y = c + mx

Question 3

So how can half-life be determined from this experiment?

Answer 3

Plot lnA against t, gradient = -λ and then t1/2 = ln2/λ