cnoncet
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Cnoncet. Lsat lseosn we rveesid wevas . Taody wl’el lrean aubot X- ayrs . Tiher pouodctirn , uess and percuatoins wehn uisng tehm . - PowerPoint PPT PresentationTRANSCRIPT
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Cnoncet• Lsat lseosn we rveesid wevas. Taody wl’el
lrean aubot X-ayrs. Tiher pouodctirn, uess and percuatoins wehn uisng tehm.
• Darw a dgaiarm of the eelmocratngeitc septcurm on the withdorebas and lbael werhe X-yars are. Wtire dwon two denrags of X-arys and percuatoins to tkae. Tlak to yuor tblae aobut how you tinhk tehy may be poudcred.
X-Rays22 April 2023
ObjectivesBe able to define keywords in the topic and select
appropriate equations.HSW: AF2 – Understanding the applications and implications of science
Used before in: P1 - waves Will use again in: lesson 2
PLTS: Team workers – Work collaboratively with others.
Used before in: p2 Will use again in: lesson 2
KeywordsReflection, refraction, diffraction, transmission, sound, light, mechanical, electromagnetic spectrum, frequency, period,
wavelength, incident ray, wave speed, echo
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Outcomes• ALL MUST be able to state 3 properties
of X-Rays, 2 uses and 3 precautions we can take around them.
• MOST SHOULD be able to describe how X-Rays are formed and their applications.
• SOME COULD explain the dangers of X-Rays and compare them to other parts of the EM-spectrum to explain why we use X-Rays in the way we do.
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Amazing survival
• http://www.youtube.com/watch?v=_Lg4Hs5X6JA
How are X-rays produced?X-rays are created when high-energy electrons suddenly lose energy. X-rays are produced artificially using a X-ray tube.
highvoltage
cathode
anode
tungstentarget
X-rays
leadshielding
Electrons from the hot cathode are fired at the tungsten target at high speed. When these high-energy electrons strike the
target, some of their energy is changed into X-rays.
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Use of X-Rays in diagnosisX-Rays are very penetrating and can
pass through the body.They are absorbed more by dense materialssuch as bone (so they are useful for checking the skeleton)and particularly metal.
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Example X-Rays
Two views of a finger on the right hand. The dislocation can be clearly seen at the joint.
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Metal absorbs X-Rays, so shows up much more clearly than bone
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Skull (with a fracture visible on the original)
Note the fillings in the teeth
Computer enhancement allows the soft tissue to be seen
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CAT Scan
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Multiple X-Ray images can be combined to give 3D images
This is called a CAT scan. Computerised Axial Tomography (tomos – Greek for slice)
video
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What do X-rays do to cells?
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X-Ray precautionsBecause X-Rays can damage cells we need
to minimise exposure by:only using X-Rays when necessary,shielding other parts of the body,focussing the X-Rays,using short exposure times
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Demonstration
• You will now be given some tasks to do in your groups to show your understanding
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Card Sort
• Sort the cards into 4 piles:
Properties Medical Uses Dangers Precautions
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X-RaysProperties Medical Uses Dangers Precautions
Travel at the speed of light
Measure bone density.
X-Rays can kill damage and kill
living cells
Use lead screens to block unwanted
raysHave high energy,
high frequencyExamine dense materials in the body like bone
X-Rays can cause cancer
Wear film badges to monitor
exposure timesHave very short
wavelengthCAT scans give
3D images of the body.
Only use when entirely necessary
Cause ionisation – by causing
electrons to split away from atoms
Highly focussed, energetic beams
can be used to kill cancer cells
Focus the beam
They are absorbed by
dense materials, such as bone or
metals.
Minimise the exposure time
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Memory Board
• You have 1 minute to examine the diagram of how X-Rays are produced.
• Then you must add the labels and describe in your own words how X-Rays are produced.
How are X-rays produced?X-rays are created when high-energy electrons suddenly lose energy. X-rays are produced artificially using a X-ray tube.
highvoltage
cathode
anode
tungstentarget
X-rays
leadshielding
Electrons from the hot cathode are fired at the tungsten target at high speed. When these high-energy electrons strike the
target, some of their energy is changed into X-rays.
How are X-rays produced?
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Think Pair Share
• The last test!• Your teacher will ask some questions. You
have 1 minute in silence to write the answer.
• 40 seconds to discuss it with your partner • 20 seconds to talk about it with your group
and hold up the best answer when your teacher says “show me”
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• Explain why they are used to check broken bones.
• How can X-Rays be dangerous?• How else do we use waves in
medicine? Compare X-Rays to other medical uses of waves to explain why we use X-Rays in the way we do.
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Pop Quiz – 1 – 8 in back of book1) State 3 properties of X-Rays2) State 3 uses of X-Rays3) State 1 danger of X-Rays4) State 3 precautions to take around X-Rays5) Describe how X-Rays are formed6) Describe how X-Rays can help us see
broken bones7) Explain the dangers of X-Rays8) Explain why would doctors not use X-Rays
to monitor unborn foetuses.
C
B
A
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Tell me two things...(for each)
• that you have done well this session• that you know now that you didn’t
know at the start• that you could do better next time• that you would like to know more
about 2