P3 01 X Rays
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39
Q1.
Explain fully why pregnant women should not normally have X-rays of the lower body.
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(Total 4 marks)
Q2.
After a person is injured a doctor will sometimes ask for a photograph to be taken of the patient’s bone structure, e.g. in the case of a suspected broken arm.
(i) Which type of electromagnetic radiation would be used to take the photograph?
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(1)
(ii) Describe the properties of this radiation which enable it to be used to photograph bone structure.
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Q3.
The picture shows a horse being prepared for an X-ray.
(2)
(Total 3 marks)
The person who will take the X-ray and the person holding the horse are wearing special aprons. These aprons have a lead lining.
Explain why the lead lining is important.
To gain full marks in this question you should write your ideas in good English.
Put them into a sensible order and use the correct scientific words.
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(Total 3 marks)
Q4.
Both X-ray machines and CT scanners are used to produce images of the body.
(a) The diagram shows an X-ray photograph of a broken leg.

Before switching on the X-ray machine, the radiographer goes behind a screen.
Explain why the radiographer does this.
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(3)
(b) The following is an extract from a newspaper article.
X-rays cause 700 new cancers each year in the U.K.
Each year there are about 125 000 new cancer cases in the UK, of which, about 700 may be due to the use of X-rays to diagnose illness.
The article was reporting on a scientific research project first published in a medical journal.
What evidence would the scientists have collected to come to the conclusion that X-rays can cause cancer?
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(2)

(c) Explain the advantage of a CT scan compared to an X-ray.
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(2)
(Total 7 marks)
Q5.
Ultrasound and X-rays are waves used in hospitals to create images of the inside of the human body. To produce the images below, the waves must enter the human body.
Ultrasound scan of an unborn child X-ray of a broken bone
© Isabelle Limbach/Thinkstock © itsmejust/iStock
(a) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate .
Describe the features of ultrasound and X-rays, and what happens to each type of wave after it has entered the human body.
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(6)
(b) It would not be safe to use X-rays to produce an image of an unborn child.
Explain why.
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(c) Ultrasound can be used for medical treatments as well as for imaging.
Give one use of ultrasound for medical treatment.
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(2)
(1)
(Total 9 marks)
Q6.
Different parts of the electromagnetic spectrum have different uses.
(a) The diagram shows the electromagnetic spectrum.
Radio waves
Microwaves Infrared
Visible light
Ultraviolet
Xrays
Gamma rays

(i) Use the correct answers from the box to complete the sentence. amplitude frequency speed wavelength
The arrow in the diagram is in the direction of increasing ......................... and decreasing ........................ .
(2)
(ii) Draw a ring around the correct answer to complete the sentence.
The range of wavelengths for waves in the electromagnetic spectrum is approximately
10 -15 to 10 4
10 -4 to 10 4
10 4 to 10 15 metres.
(1)
(b) The wavelength of a radio wave is 1500 m.
The speed of radio waves is 3.0 × 10
8 m / s.
Calculate the frequency of the radio wave.
Use the correct equation from Section B of the Physics Equations Sheet.
Give the unit.
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Frequency = ........................................
(c) (i) State one hazard of exposure to infrared radiation.
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(ii) State one hazard of exposure to ultraviolet radiation.
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(d) X-rays are used in hospitals for computed tomography (CT) scans.
(i) State one other medical use for X-rays.
(3)
(1)
(1)

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(ii) State a property of X-rays that makes them suitable for your answer in part (d)(i) .
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(1)
(1)
(iii) The scientific unit of measurement used to measure the dose received from radiations, such as X-rays or background radiation, is the millisievert (mSv).
The table shows the X-ray dose resulting from CT scans of various parts of the body.
The table also shows the time it would take to get the same dose from background radiation.
Part of thebody
Abdomen
Sinuses
Spine
X-ray dosein mSv
9.0
0.5
4.0
Time it would take to get the samedose from background radiation
3 years
2 months
16 months
A student suggests that the X-ray dose and the time it would take to get the same dose from background radiation are directly proportional.
Use calculations to test this suggestion and state your conclusion.
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(3)
(Total 13 marks)
M1.
idea that X-rays cause mutations gains 1 mark but X-rays can cause/increase chance of mutations gains 2 marks
mutations usually harmful/produce abnormal growth serious effect on growing foetus/rapidly growing cells each for 1 mark
[4]
M2.
(i) X-rays or gamma rays for 1 mark
1
(ii) passes through flesh; stopped by bone/absorbed for 1 mark each
2
[3]
M3.
Quality of written communication award for a sensible sequence of two points
1
X-rays do not go through lead accept lead protects them from the X-rays accept not exposed to X-rays
1
lead stops / reduces risk of X-rays harming / damaging / killing (persons) cells accept X-rays (may) cause cancer

accept organs for cell do not accept references to electric shock do not accept stops bones of people showing on X-ray answers involving the horse wearing an apron are incorrect references to gamma rays are incorrect
1
[3]
M4.
(a) X-rays are ionising or
X-rays kill / damage cells accept cause cancer any stray X-rays are absorbed by screen which reduces the radiation dose to the radiographer
1
1
1
(b) medical records / X-ray records of people with cancer
1
1
(c) a CT scan gives a 3D image therefore the image can be observed from different directions
1
1
M5.
(a) Marks awarded for this answer will be determined by the Quality of
Written Communication (QWC) as well as the standard of the scientific response.
Examiners should also refer to the information in the Marking guidance , and apply a ‘bestfit’ approach to the marking.
0 marks
No relevant / correct content.
Level 1 (1-2 marks)
There is a basic description of either wave
OR
[7]

What happens to either wave when they enter the body. However there is little other detail.
Level 2 (3-4 marks)
There is either:
A clear description of BOTH waves
OR
A clear description as to what happens to BOTH waves inside the body
OR
A clear description of ONE of the waves with clear detail as to what happens to either wave inside the body.
Level 3 (5-6 marks)
There is a detailed description of BOTH of the waves
AND
A detailed description as to what happens to EITHER wave inside the body.
Examples of the points made in the response:
Description of an X-ray
• X-rays are electromagnetic waves / part of the electromagnetic spectrum do not allow a description of a property – eg X-rays travel
• X-rays are (very) high frequency (waves) through a vacuum / at the speed of light
• X-rays are (very) high energy (waves)
• X-rays have a (very) short wavelength
• Wavelength (of X-rays) is of a similar size to (the diameter of) an atom
• X-rays are a transverse wave correct description acceptable – oscillations / vibrations are perpendicular (at 90°) to direction of energy transfer
• X-rays are ionising radiation
Description of ultrasound
• ultrasound has a frequency above 20 000 (hertz) or ultra sound is above 20 000 hertz
• ultrasound is above / beyond the human (upper) limit (of hearing) accept ultrasound cannot be heard by humans
• ultrasound is a longitudinal wave correct description acceptable – oscillations / vibrations (of particles) are parallel (in same direction) to direction of energy

transfer
Statement(s) as to what happens to X-rays inside the human body:
• X-rays are absorbed by bone
• X-rays travel through / are transmitted by tissue / skin
Statement as to what happens to ultrasound inside body:
• ultrasound is (partially) reflected at / when it meets a boundary between two different media
• travel at different speeds through different media
(b) (because the X-rays) are ionising accept a description of what ionising is
(they will) damage cells instead of cell, any of these words can be used:
DNA / genes / chromosomes / nucleus or mutate cells / cause mutations / increase chances of mutations or turn cells cancerous / produce abnormal growths / produce rapidly growing cells do not accept they can be dangerous (to human health) do not accept damage to soft tissue or kill cells
(c) any one from:
• removal / destruction of kidney / gall stones
• repair of damaged tissue / muscle accept examples of repair, eg alleviating bruising, repair scar damage, ligament / tendon damage, joint inflammation accept physiotherapy accept curing prostate cancer or killing prostate cancer cells
• removing plaque from teeth cleaning teeth is insufficient
6
1
1
1
[9]

M6.
(a) (i) frequency wavelength
(ii) 10 -15 to 10 4
(b) 2.0 × 10
5 correct substitution of
3.0 × 10
8 / 1500 gains 1 mark
Hz
(c) (i) (skin) burns
(ii) skin cancer / blindness
(d) (i) any one from:
• (detecting) bone fractures
• (detecting) dental problems
• treating cancer
(ii) any one from:
• affect photographic film
• absorbed by bone
• transmitted by soft tissue
• kill (cancer) cells answer must link to answer given in (d)(i)
(iii) 9 / 36 = 0.25
0.5 / 2 = 0.25
4 / 16 = 0.25 accept:
36 / 9 = 4
2 / 0.5 = 4
16 / 4 = 4 conclusion based on calculation two calculations correct with a valid conclusion scores 2 marks
1
1
2
1
1
2
1
1
1
1

one correct calculation of k scores 1 mark
E1.
Though the majority of candidates gained most of the credit for this question, relatively few candidates gained the mark available for pointing out that the rapid growth/cell division of the developing baby would make it especially prone to detrimental mutations. (Some candidates did, however, make a similar point with respect to the mother’s reproductive cells, ie. answered a rather different question.)
1
[13]
E2. Generally well answered.
E3.
Providing of a copy of the Electromagnetic Spectrum enabled many candidates to correctly identify the types of waves utilised in various applications, but few candidates chose radio as the answer to part (a)(i). In part (b) few candidates realised the commonality of the speed of these waves.
E5.
(a) Very few candidates obtained level 3 (5 or 6 marks), about half obtained level 1 (1 or 2 marks). In general, the responses regarding X-rays were answered in more detail than ultrasound. Many candidates were able to describe what the wave did, but failed to give accurate or detailed descriptions of the waves. Wavelength and frequency descriptions were often muddled. In many wrong responses, candidates failed to answer the question posed, often just appearing to write down any facts they had learned.
(b) Almost half of the candidates failed to gain any mark on this question. Often wrong responses detailed how X-rays affected the human body, organs or tissues; rather than damage at a cellular level.
(c) Less than one third of candidates could give a medical treatment using ultrasound. The most common correct response related to the treatment or removal of kidney stones.
Many candidates with incorrect responses failed to note that the question aske d for ‘other than imaging’ and stated scans of a fetus as their answer.