development of model of atom

Question 1

what did Dalton believe?

Answer 1

Dalton thought atoms were hard spheres and that elements had only one type of atom.

Question 2

what did J.J thompson discover?
how did he describe atoms?

Answer 2

J.J. Thompson discovered the electron (tiny negatively charged particle) and described atoms like ‘plum puddings’ with negative charges embedded in a cloud of positive
charge.

Question 3

what did Geiger and Marsden’s experiments involve? what did it show?

Answer 3

Geiger and Marsden’s did experiments firing positive alpha particles at gold foil which
showed atoms could not be solid.

Question 4

what did Rutherford propose?

Answer 4

Rutherford proposed that the positive charge of an atom is in a small centre which he called the nucleus and electrons orbit this nucleus. ( This is the nuclear model)

Question 5

what did Niels Bohr suggest? when?

Answer 5

In 1914 Niels Bohr suggested electrons orbit at set distances in energy levels ( or shells).

Question 6

what did James Chadwick discover? when?

Answer 6

In 1932 James Chadwick discovered the neutron which has no charge and has the same mass as a proton