Radiation Flashcards
What three types of radiation are there?
Alpha, beta and gamma
Where does radiation come from?
Unstable nuclei
List the types of radiation in order of increasing penetration ability
- Alpha-sheet of paper
- Beta-3mm aluminium
- Gamma-3m concrete
What is an alpha particle?
Effectively a helium nucleus-2 photos and 2 neutrons +2 charge
What is a beta particle?
An electron -1 charge
What is a gamma ray?
An electromagnetic wave with no charge
What is the ionising ability of alpha?
Very strong
What is the ionising ability of beta?
Moderate
What is the ionising ability of gamma?
Weak
What is ionisation?
The process of removing an electron from an atom atom
How do use a magnetic field to separate radiation
A magnetic field causes a moving charged particle to be deflected. The direction depends on the charge
How do you use an electric field to separate radiation?
Pass it through two electrodes. The particles will move towards the opposite electrode
What is an ionic half life?
The time taken for half of the atoms to decay
What problems does radiation cause?
- Mutations
- Damage to cells and tissue
- Disposal of waste
What was the Geiger-matsden experiment?
- They fired alpha particles at gold leaf
2. Most went straight through. Some were deflected. Some bounced back
What was Rutherford’s atom like?
That the atom was mostly empty space with the tiny nucleus in the middle as opposed to spread out
What happens in nuclear fission?
- Uranium 235 breaks apart when it is struck by a low-charge neutron
- Releases KE as gamma rays and decay fragments
- The parent nucleus(235) froduces two daughter nuclei.
- If these are absorbed by other fissile nuclei then a chain reaction ensues.
What does the moderator do in nuclear fission?
Absorb some of the energy of fast neutrons so they are absorbed easily to sustain the chain reaction
What do the control rods do in nuclear fission?
Absorb neutrons to eliminate them. Can be raised to speed up the reaction or lowered to shut down the reaction
