C1-Atomic Structure

Question 1

What is the charge of the nucleus? why?

Answer 1

Positive as it contains positive protons and neutral neutrons.

Question 2

Why do atoms have no charge?

Answer 2

Because the charges of the positive protons and the negative electrons cancel each other out.

Question 3

What is the charge of the proton?

Answer 3

+1

Question 4

What is the charge of the electron?

Answer 4

-1

Question 5

What is the charge of the neutron?

Answer 5

0

Question 6

What is the relative mass of a proton?

Answer 6

1

Question 7

What is the relative mass of a neutron?

Answer 7

1

Question 8

What is the relative mass of an electron?

Answer 8

0.0005

Question 9

Where is the mass of an atom concentrated?

Answer 9

In the nucleus

Question 10

Who created the plum pudding model?

Answer 10

J.J Thompson

Question 11

Describe John Dalton’s model of the atom.

Answer 11

A positive sphere of solid mass with negative electrons randomly dotted in it.

Question 12

Which subatomic particle was discovered first?

Answer 12

The electron

Question 13

Which subatomic particle was discovered last?

Answer 13

The Neutron

Question 14

Who discovered the neutron?

Answer 14

James Chadwick

Question 15

Describe the alpha scattering experiment. What did it show?

Answer 15

Positive alpha particles were fired at a sheet of gold foil. Most passed through, but a few were deflected or bounced back. This showed that the atom is mostly empty space with a small, central, positively charged nucleus.