History Of The Atom Flashcards
1
Q
Who was Democritus?
A
- He proposed the idea of an atom
* said it was the smallest particle that could not be split any further
2
Q
What was daltons theory?
A
- all of the same atoms made up an element
- all elements had different atoms
- atoms were tiny
- atoms cannot be divided
3
Q
What was Thompson’s plum pudding model?
A
- found that there is a sea of electrons
* found this using a cathode ray
4
Q
What was rutherfords experiment?
A
- Fired alpha particles at thin sheet of gold foil
- measured deflection of particles- most particles were not deflected
- small proportion was deflected at a large angle
5
Q
What did rutherfords experiment show?
A
- most of the mass of an atom was in the centre
- negative electrons orbit positive nucleus
- positive and negative charges balance to make atom neutral
6
Q
What did Bohrs model show?
A
- found that electrons orbit electrons on PATHS
* provided explanation for difference in energy of electrons at different distances from nucleus
7
Q
Who discovered the proton?
A
Rutherford
8
Q
Who discovered the neutron?
A
Chadwick
