Radiation

Question 1

What are the different types of ionising radiation

Answer 1

• Alpha
• Gamma
• Beta

Question 2

Describe alpha radiation

Answer 2

• helium nucleus. 4 on the top and 2 on the botttom. Mass and atomic number
• low penetrating (1cm or 2cm in air)
• Deflects in a magnetic field
• stopped by papper
• very high ionsising

Question 3

Decribe beta radiation

Answer 3

• Its an electron. 0 on the top and -1 on the bottom. With a negative charge
• low-ish penetrating power (1m in air)
• defelects in magnetic field
• stopped by 5mm of aluminium
• medium ionising power

Question 4

Decribe gamma radiation

Answer 4

• it’s a wave. 0 on top and bottom
• almost infinite penetrating power
• doesn’t deflect in magnetic field
• stopped by 5cm of lead or 1m of concrete
• low ionising

Question 5

What is halflife

Answer 5

The time it takes for the total number of radioactive atoms in a sample to decrease by half

Question 6

What does an atom look like

Answer 6

Protons and neutron in the nucleus (centre) and electrons orbitting in shells around it

Question 7

What are the uses of radiation

Answer 7

• gamma-emmitter can track blood flow or highlight gas leekages
• carbon dating (how old things are by amount of radiation in them)
• Radiotherapy (destroying cancer cells)

Question 8

What is decay

Answer 8

When an unstable atom loses mass or energy

Question 9

What is an isotope

Answer 9

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

Question 10

What is ionisation

Answer 10

The addaition or removal of electrons in an atom to become more stable

Question 11

What is nuclear radiation

Answer 11

The energy or particles from a radiactive nucleus

Question 12

What are the conclusions from rutherfords expeeriment and why

Answer 12

• some particle were undivieated: Atoms are mostly empty space
• some particles were rebounded: Atoms contain a small and heavy nucleus
• some particles were deflected but still coninued: Atoms Nucleus has a strong positive charge

Question 13

What was Runterfords experiment

Answer 13

• in 1912
• shoot alpha particles at thin sheet of gold
• see how the particles travel

Question 14

Is alpha radiation dangerous

Answer 14

• it ionises with the first 1cm-2cm air infront of it before it reaches you and can be stopped by paper
• however if inside your body it can make you ill and kill

Question 15

Describe the plum pudding model

Answer 15

• It is a sphere of positive charge with negative electrons embeded. Like a plum pudding
• Helped us understand charge

Question 16

Describe rutherfords model

Answer 16

We now have a nucleus in our atoms and understand them much better

Question 17

Describe bhor’s model

Answer 17

• a nucleus being orbitted by shells of electrons

- helps us understand energy levels and electron orbiting

Question 18

How do you work out neutrons

Answer 18

Nucleons(top number) MINUS protons (bottom number)

Question 19

What is radioactive activity

Answer 19

The number of emissions per second

Question 20

What is the similarity and difference between nuclear radiation and light

Answer 20

Similar: Both are radiated and absorbed
Differ: Radiation is ionising

Question 21

How do you detect radiation

Answer 21

• geiger Muller Tube
• Photographic film

Question 22

What can radiation be

Answer 22

Particles and waves

Question 23

Why can’t we say when a nucleus will decay

Answer 23

Because the process is random

Question 24

Nuclear radiation is emitted from where?

Answer 24

The nucleus

Question 25

How do you calc the activity of a source

Answer 25

• turn the time into seconds

- divide the particles it emits by those seconds

Question 26

What is the mass number

Answer 26

The top number (protons + neutrons)

Question 27

What is the atomic number

Answer 27

The central bottom number

Question 28

What is an ion

Answer 28

An atom that has lost one or more of its electrons.

Question 29

What is Radioactive decay

Answer 29

Radioactive decay is the emission of energy in the form of ionizing radiation

Question 30

What is contamination

Answer 30

Radioactive particles Getting onto or into an object

Question 31

What do you need to be careful of when working with radiation

Answer 31

• exposure and physical contact with radioactive substances

Question 32

What are the risks with radioactive materials

Answer 32

• Ionising radiation can enter living cells and ionise with them.
• This damages them (killing them or causing cancer)

Question 33

What is irradiation

Answer 33

Exposure to radiation, we are always being irradiated by background radiation. Irritating something doesn’t make it radioactive.

Question 34

Why is contamination dangerous

Answer 34

• the contaminating atoms might decay and release radiation

- Can harm you if it gets inside your body.

Question 35

How does the different radiation types cause harm in Irradiation

Answer 35

• Outside the body beat and gamma are the most dangerous because they can be emitted and penetrate the body and reach your organs.
• ## Alpha is the least dangerous because of its low penetration levels

Question 36

How does the different radiation types cause harm in contamination

Answer 36

• alpha is the most dangerous because they can do all their damage in a localised area
• Beta is less damaging because it’s radiation is absorbed over a wider are, and some passes out of the body all together
• Gamma sources are the least dangerous because they mostly pass straight out due to them having the lowest ionising power.

Question 37

What is background radiation

Answer 37

The radiation that exists around us all of the time. It is from either natural or artificial sources.