98 - Atomic Structure Flashcards
What was the plum pudding model?
Atoms were positively charged spheres with negative electrons in them
What did Rutherford and Marsden expect to happen?
Positively charged alpha particles would be slightly deflected
What actually happened to the alpha particles?
Most went straight through the foil, a few bounced back
Why did some alpha particles bounce back?
They came very close to the positive nucleus and were repelled
Why did most of the alpha particles travel straight through the foil?
There is a vast amount of space between the atom nucleus and electrons
What did Rutherford and Marsden deduce about the nucleus from their experiment?
Must be positively charged
Must take up most of the atom’s mass
Must be extremely small
What are the charges and masses of protons and neutrons?
P - mass 1, charge +1
N - mass 1, charge 0
Why do atoms have no overall charge?
Proton number = electron number
