Topic 4 (atomic structure)

• How many protons and neutrons does an alpha particle have?

  2 protons and 2 neutrons
• What is a beta particle made of?

  1 electron
• what is gamma radiation made of?


  a wavelength
• what is the atomic mass of alpha, beta and gamma particles?

  Alpha: 4 Beta: 0

  Gamma: 0
• what is the speed of alpha, beta and gamma particles?

  Alpha: Slow

  Beta: Moderate

  Gamma: Speed of light
• what is the penetration power of alpha, beta and gamma particles?

  Alpha: Low. Beta: Moderate

  Gamma: High
• what is the ionising power of alpha, beta and gamma particles?

  Alpha: High Beta: Moderate

  Gamma: Low
• what us the effect of the magnetic field of alpha, beta and gamma particles?

  Alpha: weakly deflected

  Beta: strongly deflected

  Gamma: it isn’t deflected
• When something has decayed by alpha, what does the mass and proton number decrease by?

  Alpha decay: Mass decreases by 4, proton number decreases by 2.
• when something has decayed by beta?, how ones the proton number change?


  increases by 1
• What is half life?

  the time required for HALF of a sample of radioactive atoms to decay
• how to calculate the count rate after an amount of half lives?

  count rate after n half lives = initial count / 2n