In chemistry, we learnt that to determine whether or not the plum pudding model was correct, they rolled a piece of

Question: In chemistry, we learnt that to determine whether or not the plum pudding model was correct, they rolled a piece of gold one atom thick. How were they able to do this in 1909, and how did they know that it was one atom thick?
- Keywords:
  atom,
  chemistry,
  gold,
  lectures,
  plum pudding model
Asked by 14millsj on 24 Jan 2017.
- Charles Footer answered on 24 Jan 2017:
  
  In 1909 microscopy was pretty good, even if not by todays standards. It’s also actually more easy to exclude something that’s one atom thick than you might think. In fact if you take a piece of selotape and a graphite pencil you can exclude a one atom thick layer of carbon called graphene just buy sticking the tape onto the lead of the pencil and pulling it off again. What you’re left with on the tape is something that gained some lucky scientists the nobel prize!!

Question: In chemistry, we learnt that to determine whether or not the plum pudding model was correct, they rolled a piece of gold one atom thick. How were they able to do this in 1909, and how did they know that it was one atom thick?