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The electromagnetic spectrumIB MYP Sciences: Flashcards

What these 14 flashcards ask

  • List the EM spectrum from lowest to highest frequency.
  • How does wavelength change from radio waves to gamma rays?
  • What speed do all EM waves travel at in a vacuum?
  • What type of wave are all EM waves?
  • Do EM waves need a medium?
  • Give a use of radio waves.
  • Give a use and a hazard of microwaves.
  • Give a use of infrared.
  • What is a hazard of ultraviolet?
  • Why do X-rays show bones?
  • Give a use of gamma rays.
  • What does ionising mean?
  • Which parts of the spectrum are ionising?
  • How are radiographers protected from X-rays?

Exam questions on The electromagnetic spectrum

  1. A science teacher in Mumbai draws the electromagnetic spectrum on the board and asks her class to compare radio waves, visible light and gamma rays. She reminds them that all electromagnetic waves are transverse and that sunlight reaches Earth across empty space.
    A radio station broadcasts at a frequency of 100 MHz. The speed of radio waves is 3 × 10⁸ m/s. Calculate the wavelength of the radio waves.2 marks
  2. In a hospital in Lagos, a patient with a broken wrist has an X-ray. The radiographer stands behind a lead screen to operate the machine. Later the hospital uses gamma rays to sterilise surgical instruments before they are sealed in packets.
    Explain how gamma rays can be used to sterilise surgical instruments.2 marks
  3. Students in Perth, Australia, investigate sun protection. They place identical UV-sensitive beads under clear plastic film coated with sun cream of SPF 15, SPF 30 or SPF 50, and under film with no cream. The beads change from white to purple in ultraviolet light. The students time how long the beads take to become fully purple in strong sunlight, and each test is done once. The times are 25 s with no cream, 95 s with SPF 15, 170 s with SPF 30 and 290 s with SPF 50.
    State a testable hypothesis for this investigation, with a scientific reason, and identify the independent variable.3 marks
See the full worksheet

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).