1. Where do alpha and beta particles come from?
Radioactive Decay
Where do alpha and beta particles come from?

2. Aims
To understand how alpha and beta decay affect the nuclei of radioactive atoms

3. Alpha radiation Made of : 2 protons and 2 neutrons Positive charge
Stopped by paper

4. Stopped by a thin sheet of aluminium
Beta radiation
Made of :
A fast moving electron
Negative charge
Stopped by a thin sheet of aluminium

5. Alpha decay Am BUT don’t try to count them!!
I have
95 protons and
148 neutrons
I’m the nucleus of an Americium atom
BUT don’t try to count them!! Am 95
243

6. Alpha decay
I could decay at any time, do you know how nervous this makes me

7. What’s going on? Am Np Neptunium!!!
Help I can’t be Americium if I’ve lost 2 protons
What am I now?
Hang on… something’s different
I’m missing 2 protons and 2 neutrons
Phew that feels better!
I'm an alpha particle
I have 2 protons and 2 neutrons
Neptunium!!!
They are over here Am 95
243 Np 93
239

8. Beta Decay
This Carbon 14 nucleus is unstable –it has too many neutrons

9. Beta Decay
One of the neutrons has changed into a proton and an electron.
Something strange is about to happen………

10. Beta Decay The nucleus now has 7 protons and 7 neutrons.
It has changed from a carbon nucleus into a nitrogen nucleus

11. Quiz Time