Radiation (yr9)

• what are the 4 types of radiation

  alpha, beta, gamma and neutron
• what instrument is radiation detected with

  a geiger-muller tube
• how does a geiger-muller tube work

  1 it detects or measures radiation when they enter the tube

  2 it clicks because the enter of (a,b or y) allows the electrons in the circuit
• how ionising is each type of radiation

  alpha- high

  beta- medium

  gamma- low

  neutron - low
• what level or radiation is each radiation

  alpha- low

  beta- medium

  gamma- high

  neutron - high
• what is alpha's charge

  +2
• what is beta's charge

  -1
• what is gamma's charge

  0
• how far is the range of each type of radiation

  alpha- short

  beta- medium

  gamma- long

  neutron - long
• what is an alpha particle 


  a fast moving helium nucleus that has 2 protons and 2 neutrons bonded together
• what is a gamma particle


  a high energy photon and a form of em radiation
• what radiation can be stopped by a hand or paper

  alpha
• what radiation can be stopped by aluminium

  beta
• what radiation can be stopped by a few cm of lead

  gamma and neutron
• what is alpha decay


  when two protons and two neutrons are joined up to form an alpha particle which is then emitted from an unstable nucleus
• what is beta decay 


  when a neutron decays into a proton and an electron then the electron is emitted as a beta particle
• what is half-life 


  the time taken for a radioactive substance to give out half its radiation
• on a graph: a steeper gradient = short half-life and a shallow gradient = a long half-life
• what is activity (in half-life) measured in

  bequerels (Bq)
• electrons will move within the atom, between the shells
• if an electron gets energy will it go up or down a shell

  up
• if an electron looses energy will it go up or down a shell

  down
• what is a photon

  a packet of energy
• the energy in a photon is proportional to the frequency
• electrons can only have a fixed amount of energy
• the number of electrons in each energy level is fixed
• why will electrons usually occupy the lowest energy level

  as it is closest to the nucleus
• how does an electron move up an energy level

  when a photon is absorbed, the electron reaches an excited state where it moves up
• what is ionisation 


  when a photon has enough energy to completely remove an electron
• which 3 parts of the em spectrum can ionize an electron

  Ultra violet, x-ray and gamma
• the frequency of the radiation emitted depends on the difference in energy between energy levels
• what does the absorption spectrum show

  a set of frequencies of radiation absorbed by an atom when excited electrons move to a higher energy level
• what does the emission spectrum show

  a set of frequencies of radiation emitted by an atom when excited electrons move from a lower energy level
• when do an electron emit radiation

  when moving from a higher or lower energy level
• what is a beta particle

  a fast moving electron
• what do unstable nuclei emit 


  radiation, meaning this material is radioactive
• What type of radiation does this equation symbol represent

  Alpha

  
• What type of radiation does this equation symbol represent

  Beta

  
• What type of radiation does this equation symbol represent 


  Gamma

  
• What type of radiation does this equation symbol represent

  Neutron