P1

• Radiation transfers energy from one place to another
• All waves on the electromagnetic spectrum travel at the speed of light
• Radio waves have a long wavelength and low frequency
• gamma rays have short wavelength and high frequency
• Electromagnetic spectrum - radio waves, microwaves, infrared radiation, visible light, ultra violet radiation, x-rays, gamma rays

  
• Radiation can be - reflected (bounce off surface), absorbed (cause heat), transmitted (pass through)
• Ionising radiation - some forms of radiation transfer enough energy to remove electrons from atoms forming unstable ions which can cause mutations leading to cancer
• All objects absorb and emitt electromagnetic radiation, the higher the temperature of a body/object, the higher frequency
• Wave - transfers energy in the direction the wave travels without transferring matter.
• Transverse wave - waves that oscillate at right angles to the direction of energy transfer
• wave speed (m/s) = distance (m) / time taken (s)
• Amplitude - distance from one wave crest to another
• Frequency - number of complete waves per second (Hz)
• wavelength - time taken for a wave to complete wave to pass a given point
• electromagnetic waves - transverse waves that transfer energy emitted from a source
• Reflection - light waves are emitted from a light source and transmitted through the air. Light bounces off surfaces and is reflected

  
• refraction - waves change direction as they pass from one medium to another. They travel at different speeds through different mediums. Higher density = slower the wave speed