Radiation
Name the three subatomic particles in an atom.
Proton, neutron and electron.
What do some atoms emit radiation from their nucleus?
Because the nucleus is unstable.
What is alpha radiation?
2 protons and 2 neutrons.
What is beta radiation?
Electron (from nucleus).
What is gamma radiation?
EM wave.
What type of radiation is the most penetrating?
Gamma.
What type of radiation is the most ionising?
Alpha.
Why is radiation dangerous?
Damages cells, may cause mutations and cancer or even lead to death.
Which type of radiation is the most dangerous at close range?
Alpha (as it is the most ionising).
Which type of radiation is the most dangerous at long range?
Gamma (as it is the most penetrating).
What do we use to measure count rate?
Geiger-Muller tube.
What is the definition of half-life?
The time it takes for the count rate to half.
What is contamination?
Unwanted presence of a radioactive substance on object.
What is irradiation?
Exposure to radiation.
What can we do to keep safe around radiation?
Minimise exposure time, physical distance, shield.
What happens to the mass number/atomic number during alpha decay?
Mass number -4
Atomic number -2
What happens to the mass number/atomic number during beta decay?
Mass number – same
Atomic number +1
What happens to the mass number/atomic number during gamma decay?
No change.
What is an ion?
An atom that lost/gained an electron.
How can we protect ourselves from contamination?
Avoid direct contact - use tongs, wear gloves, wear a mask, wear protective clothing.
How is an alpha particle different from a helium atom?
It has no electrons.
Alpha Radiation is stopped by...
Paper or a few cm of air.
Beta Radiation is stopped by...
A few mm of aluminium or one metre of air.
Gamma Radiation is stopped by...
Thick lead or concrete.
What is mutation?
Change in DNA (caused by ionising radiation) which can lead to cancer.