Radioactivity And Particles Flashcards
What are atoms made from
Protons, neutrons and electrons
What is bigger mass number or atomic number
Mass number
What is the atomic number
The number of protons in the nucleus
What is the mass number
The number of protons and neutrons in the nucleus (nucleons)
What is an isotope
An isotope is an atom of the same element that has the same atomic number but different mass number
Wha are the 3 types of ionising radiation
Alpha, Beta and Gamma
What is alpha decay
A helium nucleus. 4 mass number, 2 atomic number
What is beta decay
A fast moving electron
What is gamma radiation
An electromagnetic wave
What does high ionising power mean
Low penetrating power
What can alpha radiation penetrate
Nothing, only a small distance in the air
What can beta radiation penetrate
Paper but cannot get through aluminium
What can gamma radiation penetrate
Aluminium but only small amounts can get through lead because it is a wave a little bit ca
What does a Geiger-Muller tube do
Measures the count rate of a radioactive source
Alpha decay
2 protons + 2 neutrons are lost
Mass number decreases by 4
Atomic number decreases by 2
Beta decay
1 neutron is converted into a proton and an electron. (Electron is ejected)
Atomic number is increased by one as a proton is gained
Mass number remains the same
Gamma decay
Mass number is unchanged
Atomic number is unchanged
Alpha equation
A = mass number
Z = atomic number
aXz———a-4Xz-2 + 4He2
Beta equation
aXz———aXz+1 + 0e-1
Gamma equation
aXz———aXz + 0gamma0
Why is count rate never 0
Because of background radiation
What is half life
The time taken for the radioactivity of a radioactive source to decrease by half its original value
What are the uses of radioactivity
Medical tracer - radioactive source put in body and then traced
Pipe tracers - radioactive source put through a pipe and then detected where there is higher numbers meaning there is a leak
Radiotherapy - High dose of radiation kills cancerous cells
Sterilisation - medical equipment is irradiated which kills all living matter
What is irradiation
When a substance is exposed to a radioactive source
