[supehr]

Hey,

I was just reading up on Rutherfords experiment with the alpha particles being shot at the gold foil. These alpha particles faced slight deflections as they passed close to electrons. I was just wondering, if alpha particles are essentially 2 protons and 2 neutrons, shouldn't they be attracted to the electrons instead of being deflected by them? Don't positives attract negatives? So why were the protons deflected when they encountered these electrons?

Thanks! 

[Arkcon]

You're misunderstanding.  The (fairly) massive, fast moving, charged alpha particles are deflected by the massive nucleus, which shows the bulk of the positive charge is there.  The electrons are too weakly charged, and not massive enough to affect alpha particles.  The experiment was supposed to show some slight deflections, and the hope was to infer the distribution of positive and negative charges.  But instead they had to re-write the atomic model.

It was mentioned in a recent thread: http://www.chemicalforums.com/index.php?topic=73862.msg267617#msg267617