The history of the atom - chemistry/physics Flashcards
What did J.J Thompson discover?
The plum pudding model
what is the plum pudding model?
A positively charged ball with negative discrete electrons embedded in it
Who discovered the nuclear model?
Earnest Rutherford
what is the nuclear model?
it is a compact nucleus with negative electrons as a cloud around it.
What was the problem with the nuclear model that Nelis Bohr discovered?
The negative electrons would rush into the atom making the atom collapse
Nelis Bohr created shells that would prevent the atom from collapsing
What did Nelis Bohr discover?
He discovered that the electrons could orbit around a shell which would prevent the atom from collapsing
What was John daltons proposal?
He proposed that the particles could be solid spheres
the different shapes of the spheres conveyed the different elements of the periodic table.
What was the proposal of Democritus?
He proposed that ‘stuff’ was created through small particles and it cannot be simplified further
He then stated that it is separated by empty space
SPEC QUESTION
why did the new evidence from the scattering experiment lead to a change in the atomic model
Before the positively charged ball was spread out but the new evidence showed that the mass of the atom was concentrated in the centre and that the nucleus is charged.
this put the plum pudding model proposal aside
SPEC QUESTION
what is the difference between the plum pudding model of the atom and the nuclear model of the atom?
the plum pudding model has a positively charged ball that is spread out
however, the nuclear model states that the positively charged ball is a compact nucleus.
