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Flashcards in Topic 5 Deck (76):
1

Which are the most energetic and the most dangerous waves

The ones with the highest frequencies (shortest wavelengths) are the most energetic

2

Dangers of gamma rays and X-rays

Can cause mutations (changes) to the dna in the cells in the body

Could kill cells or cause cancer

3

Dangers of ultraviolet

UV in sunlight can damage skin cells, causing sunburn

Overtime exposure to UV can cause skin cancer

UV can also damage the eyes leading to eye conditions

4

Infrared dangers

Infrared radiation transfers thermal energy. Too much infrared radiation can cause skin burns

5

Dangers of microwaves

Heat water
So they can the water inside our bodies
Heating cells can damage or kill them

6

Use of gamma rays

To sterilise good and medical equipment

In scanners to detect cancer

To treat cancer

7

Use of x rays

To look inside objects including medical x-rays to look inside bodies

In airport security scanners, to see what people have in their luggage

8

Use of ultraviolet

To detect security marks made using special pens

Inside fluorescent lamps

To detect forged banknotes

To disinfect water

9

Use of visible light

Allows us to see, lights up rooms and streets, building and roads

Photography

10

Use of infrared

In cooking (by girls and toasters)

To make thermal images (images using heat) used by police and rescue services

In short range communications such as between laptops or other small computers

In remote controls for TVs and other appliances where the signal only has to travel short distances

To send information along optical fibres

In security systems such as burglar alarms to detect pills moving around

11

Used of microwaves

In mobile phones, and to communicate by satellite transmissions

For cooking (in microwave ovens)

12

Used of radio waves

Broadcasting radio and TV programmes

Communicating with ships, aeroplanes and satellites

13

Radiation is absorbed or emitted when

Electrons jump between energy levels

14

Electrons can only exist in atoms at certain

Well defined energy levels

15

What do the energy levels in atoms depend on

Depend on the atom and the electrons inside the atom can move between the shells or leave the atom completely

16

Electromagnetic radiation is emitted or absorbed by atoms based on wether

Energy is given out of taken in

17

Electrons move up energy levels when they

Absorb energy and they fall down to lower energy levels when they emit energy

18

Electrons move from a lower energy to a higher energy level when

The correct amount of energy is absorbed

19

Electromagnetic radiation is emitted when electrons

Fall down from a higher to a lower energy level

20

Where can energy also be emitted from?

The nucleus of unstable atoms

21

What do protons and neutrons also occupy

Energy levels in the nucleus in the same way tht electrons do in the atom

22

When energy changes occur in the nucleus

High energy gamma rays are emitted

23

Gamma-rays can be emitted over a large range of frequencies depending on

The energy levels within the nucleus

24

Explain the energy changes that occur within the electron levels of the atom

Electrons can move between energy levels if they absorb or emit electromagnetic radiation

When they absorb electromagnetic radiation they move up energy levels and when they emit electromagnetic radiation they move down energy levels

25

The energy of electromagnetic radiation that is emitted or absorbed has to match the

Difference between the energy levels that the electron is moving between

26

Which energy changes are greater the ones in the nucleus or this seen between electron energy levels

In the nucleus

27

Atoms have a nucleus containing

Protons and neutrons

28

What move around the nucleus of the atom

Electrons

29

Protons =

Electrons

30

+ charged =

- charges so no overall charge

31

All atoms have a

Nucleus

32

What charge has a nucleus for

Positive because it contains protons which have a positive charge

And neutrons which don’t have a charge

33

The nucleus contains how much mass of the overall atom?

More than 99%

34

Total number of protons in an atoms nucleus must be the same as th

Total number of electrons in the shapes

35

Electrons in atoms always

Orbit the nucleus and have a negative charge

36

Atoms are always

Neutral because the pos cancels out the neg charge from the electrons

37

Nucleus of an atom of an Element my contain different numbers of

Neutrons

38

What’s a molecule

Two or more atoms bonded together

39

A molecule is about ___ times the diameter of an atom and about _____ times the diameter of a nucleus

10

10^6

40

Gases such as ________ are molecules

Oxygen and carbon dioxide

41

What is water

A molecule

42

Diameter of an atom is about

10^-10

43

Diameter of the nucleus is about

10^-15

44

All atoms of a particular element have the same number of

Protons

45

The number of protons in each atom of an element is called the

Atomic number or proton number

46

Protons and neutrons in an atom is the

Mass number of nucleon number

47

Atoms of a particular element always have the same number of protons but different numbers of

Neutrons

48

Atoms with the same number of protons but different number of neutrons are

Isotopes of the same element

49

What determines an element

Number of protons

50

What can electrons do

Move between energy levels, or they can leave the atom completely

51

An electron will move from a lower to a higher orbit if

It absorbs electromagnetic radiation

52

An electron will move from a higher to a lower orbit if it

Emits electromagnetic radiation

53

Electrons can leave an atom by:

Absorbing electromagnetic radiation of enough energy so that they can escape the pull of the nucleus
The three types of electromagnetic radiation that have enough energy to do that are UV, X rays and gamma rays


Being hit by a particle such as an alpha particle or beta particle

54

Alpha beta gamma and neutron radiation are emitted by

Unstable nuclei

55

What’s the process of nucleus decay

Tcompletely random so it’s not possible to determine exactly when

56

Some elements are radioactive because their

Nuclei are unstable

57

What does it mean having an unstable nuclei

They will undergo radioactive decay and change into other elements

58

Unstable nuclei will decay when

Alpha beta gamma or neutron radiation is emitted

59

An alpha particle is a

Helium nucleus
It is composed of two protons and two neutrons it has a charge of +2 and is the heaviest of the particles emitted by unstable atoms

60

What’s a beta particle

An electron

61

What charge does an electron have

-1

62

A positron is an

Anti-electron and has a charge of +1

63

A gamma ray is a form of

High-energy electromagnetic radiation. It has no mass or charge

64

Charge of a neutron

Zero

65

Alpha and beta particles and gamma-rays can collide with atoms which

Ionises then by causing them to lose electrons

66

Properties of radiation

Neutrons:

Not directly ionising

Have a very high penetrating power due to them having no charge and not interacting strongly with matter

Can travel through humans and building for long distances before being stopped

67

Alpha particles

Will travel around 5cm in air

Very ionising

Can be stopped by a sheet of paper

68

Beta particles

Will travel a few metres in air

Moderately ionising

Can be stopped by aluminium

3mm thick

69

Gamma rays

Will travel a few kilometres in air

Weakly ionising

Need thick lead to stop them

70

Low levels of radiation are present around you...

All the time

71

What’s background radiation

Both natural and man made

72

Background radiation is exposing us to

Ionising radiation

73

Background radiation is made up of many things such as

Ground and buildings

Medical

Nuclear power

Cosmic rays

Other

Food and drink

Random gas

74

What can be used to measure and detect radiation?

Photographic film and a Geiger-müller tube

75

What is the Geiger-müller tube

Is used to detect nuclear radiation
It is connected to a counter or rate meter which shows the amount of radiation that has been detected

76

Detecting radiation

In 1896 henri becquerel discovered that uranium sky’s would lead to the darkening of a photographic film even if it was wrapped up so that no light could reach it

Radiation was being emitted from the uranium nuclei and this was responsible for the darkening of the film this is now made use of in the nuclear industry as workers will wear a film badge to determine if they are being exposed to different forms of nuclear radiation