Electromagnetic waves

What are electromagnetic (EM) waves?

↳ Transverse waves that transfer energy from their source to an absorber

How are EM waves grouped?

↳ Wavelengths and frequencys

What is the use of radio waves and why (3)?

↳ Tv/radio signals

↳ Can travel long distances through air

↳ Can bend around obstructions

What is the hazards of radio waves (2)?

↳ Penertrate the body

↳ Internal heating

What is the use of microwaves and why (4)?

↳ Sattelite communication

↳ Cooking food

↳Can reach stattelites

↳ Can penetrate into food and are absorbed by water molecules in food

What is the hazards of mixcrowaves (2)?

↳ Penertrate the body

↳ Internal heating

What is the use of infared waves and why (5)?

↳ Eletric heaters

↳ Cooking food

↳ Infared cameras

↳ All hot objects emmit infared waves so sensors can detect them

↳ Can transfer energy quickly

What is the hazards of infared waves?

↳ Damage skin cells

What is the use of visible waves and why (2)?

↳ Fibre optic communication

↳ Short wavelengths means visible light carries more information

What is the hazards of visible light waves?

↳ Can damage the retina

What is the use of UV waves and why (4)?

↳ Energy efficient lights

↳ Tanning beds

↳ Some chemicals in light bulbs can absorb UV and emit visible light

↳ Carries more energy then visible light

What is the hazards of UV waves (4)?

↳ Damage skin cells

↳ Skin ageing

↳ Increased risk of skin cancer

↳ Blindness

What is the use of X-ray waves and why (4)?

↳ Medical imagaing

↳ Treatments

↳ Pass easily through flesh but not denser

↳ Kill cancer cells as it kills living cells

What is the hazards of X-ray waves (3)?

↳ Damage/kill cells

↳ Cause mutations of genes

↳ Lead to cancers

What is the use of gamma rays and why (5)?

↳ Medical imagaing

↳ Treatments

↳ Pass easily through flesh but not denser

↳ Kill cancer cells as it kills living cells

↳ Kill harmful bacteria

What is the hazards of gamma rays (3)?

↳ Damage/kill cells

↳ Cause mutations of genes

↳ Lead to cancers