Section 1: Particles and Radiation

Question 1

What gives different elements their characteristics?

Answer 1

Electrons, Protons and Neutrons (the smaller particles that make up the atom)

Question 2

What is found in the nucleus of the atom?

Answer 2

Protons and Neutrons

Question 3

What are protons and neutrons both known as?

Answer 3

Nucleons

Question 4

What is most of the atom made up of?

Answer 4

Empty space

Question 5

What is the charge and mass of a Proton?

Answer 5

Charge = +1.60x10^-19
Mass = 1.67x10^-27 kg

Question 6

What is the charge and mass of a Neutron?

Answer 6

Charge = 0
Mass = 1.67x10^-27 kg

Question 7

What is the charge and mass of an Electron?

Answer 7

Charge = -1.60x10^-19
Mass = 9.11x10^-31 kg

Question 8

What are the relative charges and relative masses of Protons, Neutrons and Electrons?

Answer 8

Proton = +1, 1
Neutron = 0, 1
Electron = -1, 0.0005

Question 9

What is the Proton number?

Answer 9

• The number of protons in the nucleus m
• sometimes called the atomic number
• has the symbol Z
• it’s the Proton number that defines the element

Question 10

What is the Nucleon number?

Answer 10

The nucleon number A.K.A Mass number has the symbol A and it tells you how many protons and neutrons are in the nucleus

Question 11

What does the nuclide notation tell you?

Answer 11

It summarises all the information about an electrons atomic structure

Question 12

What does specific usually mean in physics?

Answer 12

Per unit mass

Question 13

What is a fundamental particle?

Answer 13

A particle that cannot be split up into anything smaller e.g. An electron

Question 14

What is the specific charge of a particle?

Answer 14

The ratio of its charge to its mass, given in coulombs per kilogram (C kg^-1)

Question 15

How do you calculate specific charge?

Answer 15

Specific charge = charge/mass

Question 16

What are atoms with the same number of protons but different numbers of neutrons called?

Answer 16

Isotopes

Question 17

What does the number of neutrons affect?

Answer 17

It affects the stability of the nucleus
In general, the greater the number of neutrons compared to the number of protons the more unstable the nucleus
•unstable nuclei may be radioactive and decay to make themselves more stable

Question 18

What are Protium, deuterium and tritium isotopes of?

Answer 18

Hydrogen

Question 19

What is isotopic data?

Answer 19

The relative amounts of the different isotopes of an element present in a substance

Question 20

How do unstable nuclei become more stable?

Answer 20

By decaying

Question 21

What are the different forces in the nucleus?

Answer 21

There are several different forces acting on the nucleons in the nucleus. 
•electromagnetic force
•gravitational force
•weak interactive forces
•strong nuclear forces

Question 22

What does the electromagnetic force cause?

Answer 22

The positively charged protons in the nucleus to repel each other

Question 23

What do the gravitational forces cause?

Answer 23

All the nucleons in the nucleus to attract each other due to their mass

Question 24

What’s the purpose of the strong nuclear force?

Answer 24

To hold the nucleus together so that the nucleons don’t fly apart

Question 25

What’s the range of he nuclear force?

Answer 25

It has a very short range of about 1 fm = 1 c 10^-15 m the size of a nucleus

Question 26

What should you remember about the strong nuclear force?

Answer 26

• the strong nuclear force is repulsive for very small separations of nucleons (0.5 fm)
• as nucleon separation increases past 0.5 fm, the strong nuclear force becomes attractive. It reaches a maximum attractive value, and then falls rapidly towards zero after about 3 fm

Question 27

How far does the electromagnetic repulsive force extend?

Answer 27

Infinitely