5-RAD-03

Outcomes

• Pupils can describe the changes on the atomic and mass number of a nucleus when a alpha or a beta or a gamma particle is released
• Pupils can balance nuclear equations
• pupils identify the good uses of radioactive particles
• pupils identify the dangers caused by the radioactive radiation

Specification References

• 7.6 describe the effects on the atomic and mass number of a nucleus of the emission of each of the three main types of radiation
• 7.7 understand how to complete balanced nuclear equations
• 7.8 understand that ionising radiations can be detected using a photographic film or a Geiger-Muller detector
• 7.9 recall the sources of background radiation
• 7.13 describe the uses of radioactivity in medical and non-medical tracers, in radiotherapy and in the radioactive dating of archaeological specimens and rocks
• 7.14 describe the dangers of ionising radiations, including:

- radiation can cause mutations in living organisms - radiation can damage cells and tissue - the problems arising in the disposal of radioactive waste

Starter

• recall and stress the idea that all radiation (alpha, beta and gamma) comes from INSIDE the nucleus

Main Body of Lesson

• start with an example of a nuclear reaction in which an alpha particle is released. Discuss that the atomic number and the mass number before reaction must be the same after the reaction.
• the atomic number decreases by 2 and the mass number decreases by 4. The initial nucleus changes into a different element.
• when introducing beta decay, recall that a beta particle is a free moving electron, so beta decay must mean 'release of a beta particle/ELECTRON from INSIDE the nucleus' HOW's that posible?????
• explain that a neutron changes into a proton - which is kept inside the nucleus - and an electron - which is released.
• the atomic number increases by 1 and the mass number stays the same
• when a alpha or a beta particle is emmited, the nucleus is usually left in an 'excited' state. It loses its surplus energy by emmitting a gamma-ray.

Plenary

• ==Homework==