Radioctivity Flashcards
What is radioactivity?
Radioactivity occurs when the nucleus of an atom is unstable .
- The nucleus decays (breaks down)
- It is random
- Produces nuclear radiation
Give the 4 radiation types.
- Alpha
- Beta
- Gamma
- Neutron
What is an alpha particle?
- 2 protons + 2 neutrons (helium nucleus) come out of nucelus very fast.
- Gets energy from falling out of nucleus.
What is a beta particle?
- High speed electron.
- Falls out of nucleus.
What is gamma radiation?
- High energy electromagnetic wave.
- Given off from nucleus
(gamma has the highest energy wave)
What is neutron radiation?
- Neutron falls off nucleus.
What is the penetrating power for alpha, beta and gamma?
Alpha: Low penetrating power.
Particles are large, easily stopped by paper
Beta: Medium penetrating power
Stopped by few mm of aluminium (low number of protons.) Blocked by sea of delocalised electrons and metal ions
Gamma: High penetrating power
* Stopped by lead/ concrete.
What is the range for alpha, beta and gamma?
Alpha: 4cm (measure with ruler) *Alpha particles are large -> will collide with air molecules and give up energy to slow down* Beta: 1-2m (measure with tape *same reason as Alpha* Gamma: km *Highest range: across the universe*
What two things make a higher ionising power (tendency to react?)
- More charge
- More energy
What is the ionising power for alpha, beta, and gamma?
- Alpha: 2+ (high ionising power)
- Beta -1 (moderate ionising power)
- Gamma 0 (Low ionising power)
- Gamma has high energy so will ionise but is less likely to do so*
What types of radiation are able to go through skin?
- Beta and gamma can go through skin.
Why is radiation harmful to humans?
- They ionise
- Cause damage to stable atoms in cells
- DNA mutations
- Lead to cancer
