CP4 Waves and the EM Spectrum (p168-171) The Electromagnetic (EM) spectrum is a continuous spectrum of ___________ waves that can travel through a __________ - they don’t need particles to travel. All EM waves travel at the speed of light: __________m/s in a vacuum. The waves can be grouped depending on their wavelength and frequency. Q1 Which colour of visible light has the longest wavelength? Q2 Which colour of visible light has the highest frequency? Q2 Which EM wave that has the most energy? Q4 What part of the electromagnetic spectrum can our eyes detect? Q5 What property of an EM wave tells us how much energy it has? Ionising radiation Which part of the EM spectrum is the most ionising? Which part of the EM spectrum is the least ionising? What’s the relationship between frequency and ionising radiation? What are the dangers of ionising radiation? Refraction – complete the lines to predict the refraction of the light rays below. Glass or water Air Producing EM waves – fill in the gaps EM waves are _________ by changes in atoms and their nuclei giving a wide range of _____________. Changes in the _________ create _________ rays and changes in an electron’s ________ level creates _______ light. Produced, nucleus, gamma, energy, frequency, visible Telescopes (Higher) - explain why telescopes that detect IR from objects in space are put into orbit around the earth. Refraction - label the angle of refraction, angle of incidence and the normal for the light entering and leaving the block.

CP4 Waves and the EM Spectrum (p168-171) Communication, TV signals Mobile phone communication, cooking Optical fibre communication Security marking, detecting forgeries Hospitals, airport security Treating cancer (radiotherapy), sterilising food and medical equipment The Electromagnetic (EM) spectrum is a continuous spectrum of transverse waves that can travel through a vacuum - they don’t need particles to travel. All EM waves travel at the speed of light: 300,000,000 m/s in a vacuum. The waves can be grouped depending on their wavelength and frequency. Internal heating of body tissues Felt as heat, causes skin burns Damage cells, mutations, cancer, cell death Damage cells, mutations, cancer, cell death Damage cells, mutations, cancer, cell death Internal heating of body tissues Q1 Which colour of visible light has the longest wavelength? Red Q2 Which colour of visible light has the highest frequency? Violet Q2 Which EM wave that has the most energy? Gamma Q4 What part of the electromagnetic spectrum can our eyes detect? Light Q5 What property of an EM wave tells us how much energy it has? Frequency Ionising radiation Which part of the EM spectrum is the most ionising? Gamma Which part of the EM spectrum is the least ionising? Radio What’s the relationship between frequency and ionising radiation? Higher frequency = more ionising What are the dangers of ionising radiation? Mutation, cancer, cell death Refraction – complete the lines to predict the refraction of the light rays below. Glass or water Air Producing EM waves – fill in the gaps EM waves are produced by changes in atoms and their nuclei giving a wide range of frequency. Changes in the nucleus create gamma rays and changes in an electron’s energy level creates visible light. Produced, nucleus, gamma, energy, frequency, visible Telescopes (Higher) - explain why telescopes that detect IR from objects in space are put into orbit around the earth. A lot of IR is blocked by the Earth’s atmosphere. Refraction - label the angle of refraction, angle of incidence and the normal for the light entering and leaving the block. Angle of incidence Angle of refraction Angle of refraction Angle of incidence