Radioactive decay

Engager GCSE Question

Self Marking

To understand the structure and properties of alpha, beta and gamma radiation Progress To evaluate the uses of different types of radioactive isotopes. To predict the properties of alpha, beta and gamma radiation. To justify how radioactive isotopes cause Ionisation.

To demonstrate good progress in this lesson Name Will… To evaluate the uses of different types of radioactive isotopes. To predict the properties of alpha, beta and gamma radiation. To justify how radioactive isotopes cause Ionisation. The Honley Learning Mindset Advocate for this lesson is… Matthew – will show resilience by not giving up if he finds something difficult.

What is Radioactivity? Some atomic Isotopes are unstable and emit radiation so they become more stable this process is called Radioactive Decay. There are three types of radiation – Alpha α Beta β Gamma γ

Types of Radioactivity Press the buttons to show the three types of radioactivity...

Connector - Ionising Radiation When radiation hits an atom it can cause it to lose electrons. The positively charged atom produced is called an ion, and this process is called ionisation. Radioactivity is measured in Becquerel (Bq) Radioactive decay is measured by using a detector called a Geiger-Muller tube (eg a Geiger Counter)

Ionisation Run the animation to see how the different forms of radiation can ionise an atom of lithium.

Everybody come to the front ‘but not too close’.

Copy down the diagram showing the penetration power of the three types of radiation.    Skin or paper stops ALPHA Thin aluminium stops BETA Thick lead reduces GAMMA Thin Plastic

The effects of a field on radiation Beta radiation has a –1 charge and a small mass so is strongly deflected Gamma radiation has no mass or charge so it is not deflected. Alpha radiation has a +2 charge but a RAM of 4 so is only weakly deflected. The effect of a magnetic or electric field on radiation depends upon the nature of the radiation.

Effects of magnetic/ electric field Alpha Beta Gamma Description Electric charge Relative atomic mass Penetration power Ionising effect Effects of magnetic/ electric field Either use information sheets for students to quickly gather the info or run through it on the board / students to complete from watching your demonstration

High energy Electromagnetic radiation Alpha Beta Gamma Description 2 Protons and 2 Neutrons High energy Electron High energy Electromagnetic radiation Electric charge 2+ -1 Relative atomic mass 4 1/1860 or negligible Penetration power Stopped by paper or few cm’s of air Stopped by few mm’s of Aluminium Stopped by cm’s of lead or metres of concreate Ionising effect Strongly Ionizing Weakly Ionizing Very Weakly Ionizing Effects of magnetic/ electric field Weakly deflected Strongly deflected No deflection Either use information sheets for students to quickly gather the info or run through it on the board / students to complete from watching your demonstration

Securing activity – complete the GCSE Question

Self Marking