Keyword Definition Key facts to remember: electromagneti A group of waves that all travel at the same speed in All EM (electromagnetic) waves are transverse waves. c waves a vacuum, and are all transverse. frequency The number of vibrations (or the number of waves) Al l EM waves travel at the same speed (velocity) through a vacuum per second. One hertz (Hz) is one wave per second. (space) at 300 million m/s.

infrared (IR) EM radiation that has a longer wavelength than EM waves are grouped based on their wavelengths and frequency. visible. We can feel infrared radiation as warmth. There are 7 basic EM waves. Radio waves, microwaves, infrared, visible light, UV, Xrays , gamma waves.

SCIENCE: Waves SCIENCE: interface The boundary between two materials. KS4 : : AutumnKS4 Term KS4 : : AutumnKS4 Term Our eyes can only detect a small part of this spectrum –visible light. refraction The change in direction when a wave goes from one medium to another. Different colours of light have different wavelengths from longest to transverse A wave in which the vibrations are at right angles to shortest: red, orange, yellow, green, blue, indigo, violet. (ROYGBIV) wave the direction the wave is travelling. or pneumonic; Richard Of York Gave Battle In Vain) ultraviolet (UV) EM radiation that has a shorter wavelength than visible light. Used to detect forged bank notes.

vacuum A place where there is no matter at all.

visible light Electromagnetic waves that can be detected by the human eye. gamma rays Electromagnetic radiation with the shortest SCIENCE: Electromagnetic Spectrum Electromagnetic SCIENCE: wavelengths and highest frequencies. microwaves Electromagnetic radiation with a longer wavelength than infrared radiation but a shorter wavelength than radio waves. radio waves Electromagnetic radiation with the longest wavelengths and lowest frequencies.

visible Electromagnetic waves that the human eye can spectrum detect. The colours that make up white light (red, Wave Speed Equation orange, yellow, green, blue, indigo, violet).

X-rays Electromagnetic radiation that has a shorter wavelength than ultraviolet radiation but a longer wavelength than gamma rays. oscillations Movements back and forth. In radio aerials, wave speed (m/s) = frequency (Hz) × wavelength (m) oscillations are repeated changes in voltage and current. Mutation A change in the DNA instructions in a cell. The electromagnetic spectrum is continuousKS4 : Autumn Term SCIENCE: Electromagnetic Spectrum low frequency low wavelength,Long high frequency high wavelength, Short microwaves spectrum Visible Gamma Part of Infrared waves X Radio rays EM - UV rays light water disinfecting notes, bank forged detecting lamps, fluorescent marking, Security rays x medical scanners, security airport of objects, structure internal the Observing cancer or treatment and of Detection cancer equipment. medical and food Sterilising satellite transmissions satellite communications, broadcasting, transmissions satellite and communications cooking, systemssecurity controls, remote optical communications, range short imaging, thermal cooking, illumination photography, Vision, Uses of EM waves fibres , television television , - Waves EM of Dangers body cells heating of internal skin burns Sunburn. conditions. and eye toskin cancer eyes, leading surface cells damage to body cells in the damage to mutation or & To Remember To effects of infrared andultraviolet waves. Compare andcontrast the harmful humans. wave can have harmful effects on different frequencies. Both types of Infrared and ultraviolet waves have GCSE 6 mark question: e) d) c) b) a) spectrumis used: Whichpart(or parts) of the electromagnetic spectrumare usedin communication. All thewaves long in the electromagnetic Practise questions: wavelengths. and frequencies Gamma waveshave the wavelength. and frequencies waveshave Radio the to sendremote controlto signals TVs? bylighthousesto warn ships of danger to sendinformation opticalalong fibres to transmit radio TV broadcastsand to transmit mobile phone signals SHORTEST LONGEST LOWEST HIGHEST The electromagnetic spectrum is continuousKS4 : Autumn Term SCIENCE: Electromagnetic Spectrum the aerial. the aerial. metaland cause oscillations in electriccircuits connected to receive radio waves. radioThe waves are absorbedbythe magnetic fields. A metal rod canbe as anused toaerial chargesoscillate, theyproduce oscillating electricand circuits. AC are made upof oscillatingcharges. As the Radio waves are producedbyoscillations in electrical How radio waves are produced: reflectedto changetheirdirection. causedamage absorbed if bybody. the Theycan also be Radio waves aretransmitted througheasily air. Theydo not forEM Communication waves HIGHER ONLYHIGHER - Long WavelengthsLong Discovering infrared: infrared: Discovering thermometer in each of thecolours in turn. to split sunlight into spectruma andput a telescope to different extents. He useda prism noticed different coloured filters up heated the his telescope to help observe thesun safely. He Herschel (1738 /title/11121 https://members.gcsepod.com/shared/podcasts schoology Usefulwebsites: anddetected? Describe how radio are waves produced are PractiseGCSE question questions: - 1822) put coloured dark, filters on