Topic 6 - Radioactivity Flashcards
Background Radiation
- Constant emission of ionising radiation from space and environment
Origins of background radiation in Earth and Space
- Earth : Radon, Foods, X-rays, Gamma-rays, Cancer treatment
- Space : Cosmic Rays
How to detect radioactivity through Geiger-Muller Tube
- Radiation enter through tube and ionises gases inside, which forms a current to flow, which makes a clicking noise
How to detect radioactivity through Photographic Film
- The ionising radiation causes changes in the crystals in the film that can be seen
How is ionising radiation released?
- Unstable nuclei in a random process
Beta +/- is an electron emitted from the…
nucleus
The most ionising decay is…
alpha
The most penetrative decay is…
gamma
1st atomic model
Indivisible mass
2nd atomic model
JJ Thompson - Plum Pudding
3rd atomic model
Nuclear model
Modern atomic model
Bohr model
Beta +/- decay release what electric charges
minus = neutrons -> protons + electrons
plus = protons -> neutrons + positron
All nuclear transmission charge and mass numbers
Alpha P=-2 M=-4
Beta - P=1 M=0
Beta + P=-1 M=0
Gamma P=0 M=0
Neutron P=0 M=-1
Uses of radiation:
- Smoke alarm
- Irradiating food
- Sterilisation of equipment
- Tracing and gauging thicknesses
- Diagnosis and treatment of cancer