Atomic Structure-Paper 1

Question 1

What is the approximate radius of an atom

Answer 1

1x10^-10 meters

Question 2

How big is an atom compared to its nucleus

Answer 2

Atom is 10,000 times bigger than a nucleus

Question 3

What is radioactive decay

Answer 3

When an unstable nucleus decays ticking out nuclear radiation

Question 4

What is half life

Answer 4

The average time is taken for half of the radioactive nuclei to decay

Question 5

What are the 4 types of nuclear radiation

Answer 5

Alpha
Beta
Gamma
Neutrons

Question 6

What is ionising power

Answer 6

The ability to remove electrons

Question 7

What is penetrative power

Answer 7

The ability to travel through a material

Question 8

Describe an alpha particle

Answer 8

2 proton 2 neutrons

Helium

Question 9

Describe the Beta particle

Answer 9

High speed electron emitted from the nucleus

Question 10

Describe gamma radiation

Answer 10

An electromagnetic wave

Question 11

What is activity

Answer 11

The rate at which a source of unstable nuclei decays

Unit is Becquerel

Question 12

What is count rate

Answer 12

The number of decays recorded each second by a detector

Question 13

What happens in alpha decay

Answer 13

Two protons and neutrons lost from the nucleus

Emitted as an alpha particle

Mass num decrease by 4 and Atomic number decreased by 2

New element formed

Question 14

What happens in beta decay

Answer 14

Neutron decays into a proton and an electron

Electron is emitted from the nucleus

Mass num stays the same atomic number increase by 1

New element is formed

Question 15

What happens in gamma decay

Answer 15

Electromagnetic wave is emitted from nucleus

Mass number stays the same

Atomic num stays the same

Question 16

What is radioactive contamination

Answer 16

The unwanted presence of materials containing radioactive atoms on other materials

Question 17

What is irradiation

Answer 17

The process of exposing an object to ionising radiation

This does not become radioactive

Question 18

What is Bohr contribution to the nuclear model

Answer 18

Suggesting adding electrons orbiting tjr nucleus

Question 19

Describe James Chadwick contribution to the nuclear model

Answer 19

Discovered the neutron through a scattering experiment

Question 20

Despite the process of nuclear fission

Answer 20

When an unstable nuclei absorbs a neutron to produce 2 smaller nuclei

Emitting 2 or 3 neutrons and game days and energy

Neutrons produced collide with another

Causing a chain reaction

Question 21

How does a nuclear power station generate electricity

Answer 21

Energy is used to heat the water which produces stream which turns the turbine which turns the generator which generates electricity

Question 22

Describe the process of nuclear fusion

Answer 22

When two small nuclei fuse to form a heavier nucleus releasing energy

Question 23

Explain how the chain reaction in a nuclear power station is controlled

Answer 23

Boron control rods are used to absorb excess neutrons which slows down the chain reaction

Question 24

Explain how the efficacy of a nucleus power station can be increased

Answer 24

A moderator is used to slow down the neutrons to increase interaction with the unstable nucleus