Atomic Structure Flashcards
John Dalton agreed with Democritus that…
Matter was made up with tiny spheres.
That could be broken up.
What did John Dalton think?
Each element was made up of a different type of atom
What did J.J Thomson discover?
Electrons could be removed from atoms.
What did Thomson suggest?
Atoms were spheres of positive charge with tiny negatives electrons stuck in them.
What did Rutherford and Marsden do?
Tried firing alpha particles at thin gold foil.
What did Rutherford and Marsden expect?
Positively charged alpha particles would be sightly deflected by the electrons in the plum pudding model.
What did the alpha particles do?
Most of them went straight through.
Odd one came straight back at them.
What did Rutheford and Marsden realise?
Most of the mass of an atom was in the centre in a tiny nucleus.
What did Rutheford and Marsden realise about the nucleus?
Must have a large positive charge.
Why must the nucleus have a large positive charge?
It repelled the positive alpha particles by large angles.
Most of the atom is just…
Empty space.
What did Rutherford and Marsden come up with?
The nuclear model of the atom.
The nucleus is tiny but…
Makes up most of the mass of the atom.
The nucleus contains…
Protons.
Neutrons.
What charge are the protons?
Positively charged.
