Radiation and Radioactivity

This resource pack was influenced by the misunderstandings revealed by the reporting of the Chernobyl accident. Many newspaper articles referred to the ‘cloud of radiation’ which had escaped from the reactor, and warned people not to drink rainwater or milk because they ‘contain radiation’. All the lessons are fully supported by photocopiable student materials together with detailed teachers' notes. Also included is a chart of radiation doses. This is now out of date but there are modern charts available here and  here .

Rationale

The order in which the main ideas are introduced in these lessons differs from that which is commonly followed. This is because research has shown that many students misinterpret the scientific ideas about radiation and radioactivity and are unable to apply scientific ideas to help them understand real-life situations where radiation and radioactivity are involved. The main misunderstandings are as follows:

*Many students appear not to be able to clearly distinguish the ideas of ‘radiation’ and ‘radioactive substance’. This confusion reflects a lack of discrimination between the two ideas in many people's ‘mental model’ of what is going on.

*Many students appear to interpret the idea that ‘radiation is absorbed’ in a way which is different from the scientific idea. They believe that objects which have been irradiated will themselves then be radioactive, perhaps just for a short time, or perhaps more permanently.

Contents

1 Source-radiation detector: a useful model

2 What happens when radiation is absorbed

3 Three types of radiation

4 Radioactivity all around!

5 Open and closed sources

6 Putting radioactive sources to use

7 Comparing sources: activity and half-life

8 Radiation dose: how much do we get?

9 Atoms, nuclei and transmutations

10 Randomness and chance.