Atomic Structure- history of the atom

Question 1

what did john dalton say about the atom?

Answer 1

atoms are small solid spheres, different spheres made up different elements.

Question 2

what did JJ Thompson say about the atom?

Answer 2

discovered the electron, showed the atom wasn’t solid and indivisible.
discovered the plum pudding model : ‘ atom is a positively charged ball with negative electrons embedded in it’

Question 3

What did Ernest Rutherford and his students say about the atom?

Answer 3

ALPHA PARTICLE SCATTERING EXPERIMENT: positively charged alpha particles were fired at a thin sheet of gold foil. Most particles passed straight through the gold foil. Small number of alpha particles were deflected. This showed that most of the atom was empty space. The nucleus was positively charged due to some of the alpha particles being deflected.

Question 4

What did Niels Bohr say about the atom?

Answer 4

Discovered that the cloud of electrons could collapse into the positive nucleus. He proposed electrons were fixed in energy shells.

Question 5

What does the Atomic model look like today?

Answer 5

Electrons do not have the same energy and shells .there are subshells. There is a nucleus which contains protons and neutrons.