Studied by 24 people
What is an isotope?
Same number of protons, different number of neutrons
What will unstable nuclei eventually do?
Decay
Why does alpha decay happen?
There are too many nucleons in the nucleus
What will alpha decay create?
A more stable nucleus (hopefully) and an alpha particle
What is an alpha particle?
Helium
Why does beta decay happen?
There are too many neutrons in the nucleus
What will beta decay create?
A more stable nucleus (hopefully) and a beta particle
What does the neutron in beta decay turn into?
A proton
What is a beta particle?
A high speed ionising electron
What happens to the atomic number in alpha decay?
Decreases by 2
What happens to the atomic number in beta decay?
Increases by 1
Why does gamma decay happen?
There is too much energy in the nucleus
What will gamma decay create?
A more stable nucleus (hopefully) and a gamma ray
What is a gamma ray?
An electromagnetic wave
What is an ion?
An atom that has lost or gained electrons
What is ionising?
Something that can make ions
What is released during ionising?
An electron
What are the dangers of ionising radiation?
DNA mutations, cancer and cell death
What type of decay is stopped by paper?
Alpha
What type of decay is stopped by 5mm of aluminium?
Beta
What type of decay is stopped by 5m of lead or concrete?
Gamma
How can radiation be detected?
Photographic film or a geiger counter
What is background radiation?
The radiation around us in the environment all the time
Give an example of natural sources of radiation:
Rocks, food+drink, cosmic rays, living things
Give an example of man made sources of radiation:
Nuclear power plants, nuclear weapon testing, medical scanners
What is radiation measured in
Bq or Becquerels
What is half-life?
The average time taken for half of the original mass of the sample to decay
What is a use of radiation?
Radiotherapy
Why is gamma used for radiotherapy?
It is highly penetrating so it goes through the body and it has low ionising power which makes it the least likely to cause more cancer
If something has a long half life is it used inside or outside the body?
Outside
If something has a short half life is it used inside or outside the body?
Inside
Why do we want the activity to drop quickly?
So the person doesn’t absorb too much radiation
Note 
Flashcard (24)