Section 1: Particles and radiation

Question 1

1 - Matter and radiation
1.1 Inside the atom

What is a nucleon?

Answer 1

A proton or a neutron in the nucleus.

Question 2

1 - Matter and radiation
1.1 Inside the atom

What holds the electrons in the atom?

Answer 2

The electrostatic force of attraction between the negatively-charged electrons and the positively-charged nucleus.

Question 3

1 - Matter and radiation
1.1 Inside the atom

What is the charge and mass of a proton?

Answer 3

Charge: +1.60 × 10^-19 C
Charge relative to proton: +1
Mass: 1.67 × 10^-27 kg
Mass relative to proton: 1

Question 4

1 - Matter and radiation
1.1 Inside the atom

What is the charge and mass of a neutron?

Answer 4

Charge: 0 C
Charge relative to proton: 0
Mass: 1.67 × 10^-27 kg
Mass relative to proton: 1

Question 5

1 - Matter and radiation
1.1 Inside the atom

What is the charge and mass of an electron?

Answer 5

Charge: -1.60 × 10^-19 C
Charge relative to proton: -1
Mass: 9.11 × 10^-31 kg
Mass relative to proton: 0.0005

Question 6

1 - Matter and radiation
1.1 Inside the atom

What is proton number/ atomic number?

Answer 6

The number of protons in the nucleus.

Question 7

1 - Matter and radiation
1.1 Inside the atom

What is nucleon number/ mass number?

Answer 7

The number of protons + neutrons.

Question 8

1 - Matter and radiation
1.1 Inside the atom

What is an isotope?

Answer 8

An atom of an element that has the same number number of protons, but different number of neutrons.

Question 9

1 - Matter and radiation
1.1 Inside the atom

What is specific charge?

Answer 9

Defined as:

Charge ÷ Mass

Units:

C kg^-1

Question 10

1 - Matter and radiation
1.2 Stable and unstable nuclei

What is the range of the strong nuclear force?

Answer 10

3-4 fm [femtometres] [1 fm = 10^-15 m]

Question 11

1 - Matter and radiation
1.2 Stable and unstable nuclei

When does the strong nuclear force change?

Answer 11

It is an attractive force from 3-4 fm down to about 0.5 fm. At distance below this, it is a repulsive force that acts to prevent neutrons and protons being pushed into each other.

Question 12

1 - Matter and radiation
1.2 Stable and unstable nuclei

What is alpha radiation?

Answer 12

Consists of alpha particles - each containing 2 protons and 2 neutrons

[Mass number: 4, Atomic number: 2]

Question 13

1 - Matter and radiation
1.2 Stable and unstable nuclei

What is the equation for alpha radiation?

Answer 13

A ‘’’’’’’’’’’ A-4 ‘’’’’’’ 4
X —–» Y ++++ α
Z ‘’’’’’’’’’’ Z-2 ‘’’’’’’’ 2

Question 14

1 - Matter and radiation
1.2 Stable and unstable nuclei

What is beta radiation?

Answer 14

Fast moving electrons

Question 15

1 - Matter and radiation
1.2 Stable and unstable nuclei

What is the equation for beta radiation?

Answer 15

A ‘’’’’’’’’’’’ A
X —–» Y +++ β- + Antineutrino [v with a hat]
Z ‘’’’’’’’’’’ Z+1

Question 16

1 - Matter and radiation
1.2 Stable and unstable nuclei

What is gamma radiation?

Answer 16

Electromagnetic radiation emitted by an unstable nucleus. Can pass through thick metal plates. Emitted by a nucleus with too much energy, following an alpha or beta emission.