history of atom

Question 1

What was John Dalton theory on the periodic table?

Answer 1

John Dalton described atoms as solid spheres, and
that those solid spheres join together to make the
elements.

Question 2

What was J.J Thompson experiments and how did it

prove Dalton wrong?

Answer 2

J.J Thompson discovered the existence of the electron from his cathode ray experiments.He created the plum pudding model to describe why the atom contains electrons yet how it is neutral.

Question 3

How did Ernest Rutherford prove the plum pudding model wrong?

Answer 3

He fired positively charged alpha particles at a very thin sheet of gold.They expected most of the electrons to pass or be slightly deflected at most ; the plum pudding model states how positive charge is uniform.The experiment disproved the hypothesis. the whole atomic model was revised. it was then believed that
all the positive charge was concentrated in a nucleus-electrons orbit the nucleus.

Question 4

What was Niels Bohr hypothesis on the atom?

Answer 4

He states that electrons orbit in fixed shells .This hypothesis was supported by the contemporary scientists of the time.

Question 5

What was James Chadwick?

Answer 5

discovered neutrons.