PHYSICS - Types of Radiation Flashcards
Look at pages 1-3
That makes so much sense now
What is radioactivity?
Radiation emitted from the nucleus of certain atoms
How can you tell if a nucleus is stable?
Depends if the number of protons and neutrons are balanced
What are isotopes?
Atoms of the same element, same atomic number but different nucleon number
(Same number of protons, different number of neutrons)
How does an unstable nucleus become stable?
Gives off radiation
What are the 3 types of radiation?
Alpha radiation
Beta radiation
Gamma radiation
What is alpha radiation?
Helium nuclei
- They got 2 protons & neutrons
- +2 charge
- Mass of 4
- Slow
What is beta radiation?
Fast moving electron
- In nucleus, neutron changes into proton & electron, electron ejected from nucleus
- Relative negative charge of -1
- Mass of 1/2000
- 1.5x10^8 fast
What is gamma radiation?
Electromagnetic wave
- 0 charge & mass
- Short wavelength & high frequency wave
- Very energetic wave due to frequency
- Travels at speed of light (3x10^8 n/s faster)
- Emits from nucleus due to too much energy
What is ionisation?
- Ability to change a neutral atom –> positive ion
- Only by knocking an electron out of its shell
- Dangerous as it causes cancer (affects DNA too)
What stops alpha?
Paper
What stops beta?
mm’s of Aluminium
What stops gamma?
cm’s of Lead
Order the 3 radiations from most penetrating to least
- Gamma
- Beta
- Alpha
Order the 3 radiations from most ionising to least
- Alpha
- Beta
- Gamma
Whats a geiger muller counter/tube?
Device that produces click sounds when ionisation takes place
3 ways of minimising dose from radioactive source
- Use tweezer
- Use perspex screen for shielding (only affective against beta)
- Minimise outside time of source
Where should radioactive sources be kept when unused
Lead-lined box
Explain how dose received depends on distance
Further away you go, smaller the dose
Set up instructions on how to find out which source is which if their labels are removed ¯_(ツ)_/¯
1) Get geiger muller counter/tube & paper
2) Place sources at suitable place and counter to get original count
3) Place paper in between sources and counter
4) Record readings
5) I mean u meant to learn what stops the radiations so yeah…
Name 8 sources of low-level background radiation
just list 3
- Cosmic rays (from space)
- Food and drink
- Medical?
- Air travels
- Ground and buildings
- Radon? (biggest contributor to bg radiation)
- Nuclear weapons testing
- Nuclear power
Name 4 natural background radiation sources
- Cosmic rays
- Food and drink
- Radon gas
- Ground and buildings
Name 2 man made background radiation sources
- Nuclear waste & Medical
Why is it not possible to predict when an unstable nucleus decays?
Decay is random
When calculating radiation emitted from a substance, what else do we have to be aware of?
Background radiation
1) What does it mean if its “corrected for background radiation”?
2) Why is it done?
3) What is background radiation & name 1
1) They gain the radiation from substance and remove “background radiation” included.
2) To gain real amount of radiation from substance
3) Radiation from environment, [you should know this]
Where is radon produced?
Why is it a health hazard?
- Inside volcanic rocks due to naturally occurring radioactive uranium disintegrating and forming radium
- Natural occurring radioactive uranium disintegrates
- Forms radium (radioactive)
- Also disintegrates forming radon
- It’s a gas emitting alpha particles
Disadvantage of nuclear powerstations
Production of nuclear waste
Name 5 methods of storing nuclear waste, advantages & disadvantages
s’pose u just list 2
1) Send into space
A: Long distance D: Expensive
2) Dump out to sea
A: Cheap D: Bioaccumulation
3) Leave it where it is
A: Free, easy D: Terrorist risk & health risks
4) Leave it on a remote island
A: Distance D: Bioaccumulation
5) Bury it underground
A: Cannot leave D: Geologic faults (may get in water)
Why should radioactive waste be monitored?
Lasts for thousands of years, still emitting radiation
How can you tell its an alpha decay?
Loss of 2 protons & neutrons (look at p. 28)
How can you tell its a beta decay?
Loss of a fast-moving electron when a neutron changes into a proton (look at p.28)
basically add a -1 on atomic number ig
How can you tell its a gamma decay?
You can’t idiot, doesn’t give off any particles
I recommend you just look at pages 28 and above
You actually right what the hell
