Episode 508: Preparation for the radioactivity topic
This can be a fascinating area for students. Over the age of 16, they can work with certain
radioactive sources, provided they are carefully supervised. One of your tasks as a teacher is to
show them how to work safely, and to convince them that it is indeed safe to do so. You can do
this by thinking first about the level of background radiation that we all live with, and showing how
to ensure that exposure during experimental work does not add significantly to this lifelong
exposure.
Episode 509: Radioactive Background and Detectors
Episode 510: Properties of radiations
Episode 511: Absorption experiments
Episode 512: Nuclear equations
Main aims
Students will:
1. Work safely with laboratory sources of ionising radiation.
2. Understand the processes of radioactive decay.
3. Use standard notation to represent nuclear processes.
4. Solve problems involving half-life and exponential decay equations.
Prior knowledge
Students should have a basic, descriptive knowledge of radioactivity. They should know that
there is background radiation; that radioactivity arises from the breakdown of an unstable
nucleus; that there are three types of radioactive emission with different penetrating powers; the
natures of alpha and beta particles and of gamma radiation; the meaning of the term ‘half-life’.
Where this leads
An understanding of radioactive processes is important in some optional topics, such as Medical
Physics.
Exponential decay equations are closely related to equations for capacitor discharge, so there is
an opportunity here to draw together two widely separated strands of Physics.
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