Alpha Scattering and Nuclear Model:

Question 1

What does the plum pudding model suggest?

Answer 1

• An atom is a ball of positive charge with negative electrons embedded into it.
  -

Question 2

Why was the alpha particle experiment carried out?

Answer 2

• Test the valdility of the plum pudding model /

Question 3

What was the alpha scattering practical?

Answer 3

• Scientists took a peice of gold and hammered it down to 1 atom thick.
• Fired alpha particles at the foil of gold.
• Observation 1: Most alpha particles passed through the foil without changing direction suggesting that the atom consists of mostly empty space.
  Observation 2: Some alpha particles deflected and changed direction when it passed through, suggesting that the nucleus of the atom has a positive charge.
• Observation 3: Few alpha particles bounced directly back from the gold foil, suggesting the centre has a great mass which when collidied causes particles to bounce back.

Question 4

What did the nucleur model look like?

Answer 4

• Empty space.
• Positive nuclues.
• ## Negative electrons.

Question 5

What did Niels bohr suggest?

Answer 5

• Electrons orbit the nuclues at specific distances rather than a general area.
• Orbits are called energy shells.
• Theory was agreed with other scientists.

Question 6

What did James Chadwick discover?

Answer 6

• Scientists had found out that the positive charge in the nuclues is due to positive particles called protons.
• Later discovered that nucleus contains nuetrons.
• These have no charge, neutral.