[Note: Links to Bitesize websites may direct you to a ‘home’ page for Radiation and the Universe- click ‘Activity’ for Radioactive Substances and scroll through until you find the appropriate page]
1) Go to http://www.bbc.co.uk/schools/gcsebitesize/science/aqa/radiation/radiocativerev1.shtml . What is an isotope? How many isotopes of hydrogen are there?
An isotope is an atoms which are from the same element but have different numbers of neutrons. Hydrogen has three isotopes.
2) Use the Bitesize pages and the ‘Y10 radioactivity’ file (especially the ‘types of radiation’ animation and videos in the ‘Radiation types- range and stopping’ file) to complete the following table:
3) (NB: Don’t worry about the ‘inverse square law’ bit about gamma radiation, this simply states that when the distance from the source is doubled, the count rate decreases by more than half (this is known as the ‘inverse square’ law).
Radiation type
Made of
Charge
Mass
Stopped by
Alpha
2 protons
2 neutrons
+2
Large
Paper
Beta
Electron formed with neutron inside
-1
Small
Aluminum
Gamma
Electromagnetic wave
0
Tiny
Lead
4) Open folder ‘ionisation’ and watch the video. Look closely at the particles emitted by the source at the end of the animation - what type of emission is this? Explain how these particles can cause an electric current to travel through air.
An electron will be taken from the surface which is attracted to the positive plate whereas the ironized particle is attracted to the negative plate which then drifts sideways. The electrons got one way and the ionized air goes the other way helping the current to flow.
5) Open folder ‘detecting radiation’. Draw a diagram in your book showing how the Geiger-Muller tube detects radioactive emissions for a count-rate to be established.
6) Open the ‘Geiger Muller Tube.exe’ folder and have a go at setting up a Geiger-Muller tube that is connected