Radioactivity

Question 1

What did J. J. Thomson discover in 1897?

Answer 1

J. J. Thomson discovered that electrons could be removed from atoms. This meant atoms weren’t the smallest thing and that there were smaller bits in an atom.

Question 2

What was the plum pudding model?

Answer 2

The plum pudding model was that atoms were spheres of positive charge with tiny negative electrons in them.

Question 3

What did Rutherford and Marsden discover in 1909?

Answer 3

They fired a beam of alpha particles at a thin piece of gold foil. The particles should have passed straight through but more were deflected back than expected.

Question 4

How did Niels Bohr tweak Rutherford’s idea?

Answer 4

He proposed a model where the electrons were fixed in orbits at set distances from the nucleus.

Question 5

What are the three subatomic particles?

Answer 5

Proton
Neutron
Electron

Question 6

What is the relative mass of an…
Electron
Proton
Neutron

Answer 6

Electron: 0.0005
Proton: 1
Neutron: 1

Question 7

What is the relative charge of an
Electron
Proton
Neutron

Answer 7

Electron: -1
Proton: +1
Neutron: 0

Question 8

What can happen when an electron absorbs electromagnetic radiation?

Answer 8

An inner electron can move up to a higher energy level, however it requires the right amount of energy.