P1.1.2 - The Model Of The Atom 2

Question 1

What did Ernest Rutherford first discover?

Answer 1

Some materials emit particles

Question 2

What are alpha particles?

Answer 2

Particles that are emitted by some materials

Question 3

What is the charge of an alpha particle?

Answer 3

Positive

Question 4

When was the alpha particle discovered?

Answer 4

1899

Question 5

Who helped Rutherford with his gold foil experiment?

Answer 5

Hans Geiger and Ernest Marsden

Question 6

How did Rutherford explain the results of his experiment?

Answer 6

He suggested that an atom is made of a tiny, positively charged nucleus that is surrounded by electrons.

Question 7

What was the rutherford model?

Answer 7

An atom containing a nucleus with randomly encircling electrons

Question 8

What happens when alpha particles hit a nucleus?

Answer 8

They bounce back

Question 9

If an alpha particle slightly veers off when going through an atom, what does this suggest?

Answer 9

There is a powerful charge somewhere in the atom

Question 10

If most of the fired alpha particles went through the atom, what does this suggest?

Answer 10

The atom is mostly empty

Question 11

If some of the alpha particles bounced back from the atom, what does this suggest?

Answer 11

There is something small and heavy in the atom

Question 12

What did Niels Bohr suggest?

Answer 12

That electrons can only move in fixed orbits

Question 13

What are Electron shells?

Answer 13

The fixed pathways that electrons move in?

Question 14

When did Niels Bohr introduce electron shells?

Answer 14

1913

Question 15

What is the diameter of an atom?

Answer 15

10 to the power of -10

Question 16

What are molecules?

Answer 16

A collection of atoms, strongly joined together or bonded

Question 17

Why was the apparatus in the Rutherford experiment placed in a vacuum chamber?

Answer 17

To stop air particles from absorbing the alpha particles

Question 18

How did they conduct the Rutherford model?

Answer 18

They used a detector consisting of a microscope focused on a small glass plate. The small glass plate was on the gold foil that had alpha particles shot at it from a small lead box. Every time an alpha particle hits the plate a light shows up that the scientists can count. The scientists used the detector to different positions and at each position they counted the amount of light showing up.