1. Radioactivity Ionising and background radiation
Three kinds of emission
Detection of radioactivity

2. Radioactive decay
Emission of particle from the nucleus of an atom

3. Isotopes
Atoms with the same number of protons but with different number of neutrons

4. Three kinds of particle emission
Type of particle
Alpha Particle
Beta Particle
Gamma Particle
Composition
2 protons and 2 neutrons (helium nucleus)
Electron
Electromagnetic radiation
Charge
positive
negative
No charge

5. Which one is most massive among the three radioactive particles?

6. Effects of Electric Field

7. Effects of Magnetic Field

8. Three kinds of particle emission
Type of particle
Alpha Particle
Beta Particle
Gamma Particle
Penetration Power
Paper
Aluminum sheet
Lead

9. Detecting Radiation
Geiger-Muller (or GM) Tube
Photographic Film

10. Ionising Radiation
When a radioactive particle collides with an atom and strips off its electrons, causing the atom to become an ion.
Which is most ionising among the three radioactive particles?

11. Radiation that naturally occurs around us
Background Radiation
Radiation that naturally occurs around us

12. Uses of radioactivity Tracers
To monitor how a substance moves in an organism
Sterilization
Radiotherapy
Treat cancer cells or tumors
Archeology
Determine age of things
Paper Industry
Monitor thickness of paper

13. Half-life
The time it takes for a radioactive sample to decay to half of its original amount