structure of an atom

• describe the differences between the plum pudding model and the nuclear model?

  plum pudding doesn't show nucleus or shells and doesn't show neutrons and protons unlike the nuclear model
• why did Rutherford's experiment lead to the plum pudding model being replaced?


  the results from the experiment meant that the plum pudding model was disproved as it was inaccurate.
• what is the significance of Rutherford's nuclear model?

  it proved that atoms had a tiny positively charged nucleus but is mostly empty
• the plum pudding model - jj Thompson


  contains gas like spheres

  mass is evenly distributed throughout

  the body is positive

  there are negative things floating within
• Rutherfords experiment 


  alpha particles are passed through gold foil

  the apparatus is in a vacuum

  there is a zinc sulphide screen

  flashes happen when alpha particles hit the screen

  the screen can be moved around the apparatus

  result = most particles passed through, some were deflected and some were reflected from the foil.
• what were the conclusions of Rutherfords experiment?


  there must be lots of empty space within the atom

  there is a positive nucleus causing the deflection

  nucleus must be small and heavy