P4 Atoms & Radiation

Question 1

<p>What is <b>nuclear fission</b>?</p>

Answer 1

<p>Nuclear Fission splits 1 nucleus into 2 or more smaller nuclei</p>

<p>This usually happens in a nuclear reactor</p>

Question 2

<p>How does nuclear fission work?</p>

Answer 2

<ul><li>A neutron collides with a large nucleus and is absorbed. This creates an unstable nucleus</li><li>This nucleus then splits into fragments. This releases large amounts of energy and more neutrons. These neutrons can then collide with other nuclei</li><li>The energy released is used to boil water, which rotates a turbine. The turbine then turns a generator, which produces electricity</li></ul>

Question 3

<p>What happens if Nuclear Fission is not controlled?</p>

Answer 3

<p>If nuclear fission is not controlled, the rate of nuclear fission can accelerate over time. This starts a chain reaction where each stage of fission produces more and more energy. This could lead to a reaction</p>

Question 4

<p>What is <b>Nuclear Fusion</b>?</p>

Answer 4

<p>Nuclear fusion joins 2 smaller nuclei to create 1 larger nucleus</p>

Question 5

<p>What is <b>radioactive decay</b>?</p>

Answer 5

<p>Radioactive decay is the process where an unstable atomic nucleus becomes more stable by randomly emiting ionising radiation</p>

Question 6

<p>What are <b>radioctive substances</b>?</p>

Answer 6

<p>Radioactive substances are substances that decay radioactively over time</p>

Question 7

<p>What does alpha radiation emit?</p>

Answer 7

<p>Alpha radiation emits a <b>helium nuclei</b>, also known as an alpha particle</p>

Question 8

<p>What does beta radiation emit?</p>

Answer 8

<p>Beta radiation emits a <b>fast-moving electron</b>, also known as a <b>beta particle</b></p>

Question 9

<p>What does gamma radiation emit?</p>

Answer 9

<p>Gamma radiation emits a high-energy electromagnetic wave</p>

Question 10

<p>What are the three primary methods of detecting radioactivity?</p>

Answer 10

<ul><li>Geiger-Muller Tube (Geiger Counter)</li><li>Cloud chamber</li><li>Photographic film</li></ul>

Question 11

<p>How does a cloud chamber detect radioactivity?</p>

Answer 11

<ul><li>A cloud chamber is a container full of air containing alcohol vapour</li><li>Ionising radiation enters the air and leaves a trail of ionised air molecules</li><li>The alcohol vapour condenses on the ionised air molecules, showing the trail of radiation</li></ul>

Question 12

<p>How does photographic film detect radioactivity?</p>

Answer 12

<p>Ionising radiation has the same effect on photographic film as light
A bright spot appears wherever the ionising radiation hits the film</p>

Question 13

<p>How does a Geiger-Muller Tube detect radioactivity?</p>

Answer 13

<ul><li>Ionising radiation enters a tube full of low-pressure gases</li><li>It ionises the atoms in the gas, knocking electrons out of the atoms</li><li>The gas can now conduct electricity and completes an electric circuit. Current flows between electrodes</li><li>The current produces a clicking noise</li><li>The count-rate is the number of decays recorded each second</li></ul>

Question 14

<p>What is <b>background radiation</b>?</p>

Answer 14

<p>Background radiation is the level of ionising radiation present from the environment</p>

Question 15

<p>What is the most ionising type of radiation?</p>

Answer 15

<p>Alpha Radiation</p>

Question 16

<p>What is the most penetrative type of radiation?</p>

Answer 16

<p>Gamma Radiation</p>

Question 17

<p>What are some different practical uses of radiation?</p>

Answer 17

<ul><li>Exploring Internal Organs</li><li>Sterilisation</li><li>Smoke Detectors</li><li>Paper Production</li></ul>

Question 18

<p>Which type of radiation is used to explore internal organs?</p>

Answer 18

<p>Gamma Radiation</p>

Question 19

<p>How do we use gamma radiation to explore internal organs?</p>

Answer 19

<ul><li>If we put a gamma-emitting isotope into a patient’s body, we can trace (follow) the radiation’s movement around the body</li><li>Gamma radiation is the most penetrating type of radiation. This means it can pass through objects more easily than alpha or beta radiation. This means gamma can leave the body without creating too much damage (ionisation)</li><li>Gamma radiation also has a short half-life. This means that the radiation vanishes quickly</li></ul>

Question 20

<p>Which type of radiation is used for sterilisation?</p>

Answer 20

<p>Gamma Radiation</p>

Question 21

<p>Which type of radiation is used in Smoke Detectors</p>

Answer 21

<p>Alpha Radiation</p>

Question 22

<p>How do we use alpha radiation in smoke detectors?</p>

Answer 22

<ul><li>A radioactive material fires alpha particles at a smoke detector</li><li>If there is smoke between the radioactive material and the smoke detector, then fewer alpha particles will reach the detector</li><li>This will set off the smoke alarm</li></ul>

Question 23

<p>Which type of radiation is used in paper production?</p>

Answer 23

<p>Beta Radiation</p>

Question 24

<p>How do we use Beta Radiation in the production of paper?</p>

Answer 24

<ul><li>We can fire beta particles through paper in a factory to make sure that the paper being produced is the right thickness</li>If the thickness of the paper changes, greater or fewer beta particles will reach the detector. Production can then be stopped</ul>

Question 25

<p>What does the

| <b>proton number (atomic number)</b> of an atom tell us?</p>

Answer 25

<p>The proton number tells us what type of element the atom is</p>

Question 26

<p>What does the <b>nucleon number (mass number)</b> of an atom tell us?</p>

Answer 26

<p>The nucleon number tells us the total number of protons and neutrons in the atom</p>

Question 27

<p>What are <b>isotopes</b>?</p>

Answer 27

<p>Isotopes are forms of an element that have the same number of protons but a different number of neutrons</p>

Question 28

<p>What are <b>Nuclids</b>?</p>

Answer 28

<p>A nuclid is a type of isotopethat refers to a specific nucleus and contain a certain number of protons and neutrons</p>

Question 29

<p>Which isotope of uranium is used in nuclear fission?</p>

Answer 29

<p>Uranium-235</p>

Question 30

<p>What is a <b>half-life</b>?</p>

Answer 30

<p>A half-life is the time it takes for number of radioactive nuclei to halve</p>

Question 31

<p>Which safety precautions should we use to reduce our exposure to radioactive elements?</p>

Answer 31

<ul><li>Reduce Exposure - Use shielding and maximise distance</li><li>Handle with protective equipment</li><li>Store in Lead-lined boxes</li><li></ul>
</li></ul>

Question 32

<p>What is <b>Contamination</b>?</p>

Answer 32

<p>Contamination is when radioactive material gets onto other materials</p>

Question 33

<p>What is <b>irradiation</b>?</p>

Answer 33

<p>Irriadiation is an exposure to nuclear radiation</p>

<p>The Object is not contaminated but is only near to a radioactive source</p>

Question 34

<p>Which type of radiation is most likely to cause cell mutations?</p>

Answer 34

<p>Alpha Radiation</p>

Question 35

<p>Why is Alpha radiation most likely to cause cell mutation?</p>

Answer 35

<p>Alpha Radiation cannot pass through skin so stays in the body</p>

Question 36

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Answer 36

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Question 37

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Answer 37

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Question 38

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Answer 38

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