IB Physics Exam Preparation – Nuclear Decay, Activity and Half-Life (Nuclear Physics)

This video is aimed at IB and A-Level students studying Physics. It can also help students preparing other diplomas that include Nuclear Decay in their cursus.

In this episode, we will be working on an exercise inspired by a past exam that deals with the Alpha Decay of Polonium into Lead. By analyzing a decay curve, we will be reviewing the concepts of the half-life and activity of a radioactive sample.

Pause the video and work it out by yourself. Then, we review the exercise together. When relevant, I remind the viewer on concepts required to solve the exercise.

You can get free access to tons of free resources like this one by visiting the website:

Music:
Intro and outro music are composed and produced by Edouard Reny.
Calm background music attributed to “Huma-Huma”
(Track names: Hydra and Nevaday-City, both available in Youtube’s Free Audio Library)

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***************** Text of the exercise ******************

1/ Polonium (A=232 Z=84) alpha decays into an isotope of Lead (Pb).
a/ Write the corresponding decay reaction. (2 Marks)
b/ Radioactive decay is said to random and spontaneous. What does this sentence mean? (2 Marks)

2/ The graph in the video is a measurement of the evolution of the activity of the sample with time.

a/ Using the graph, determine the half life? (1 Mark)

b/ What assumption did you make regarding the measurement of the activity when answering a/? (1 Mark)

c/ Complete the graph up to a time of 0.6 seconds (2 Marks)

d/ What would be the activity of the sample after 0.75 second. (2 Marks)

e/(HL) Consider a new sample of 1Kg of Polonium 216. How much Lead would have been produced after 0.5 seconds. (2 Marks)