Electromagnetic waves

Electromagnetic waves

What are electromagnetic (EM) waves?

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

↳ Eg- infared waves transfer emmited from a hot object transfers thermal energy

How are EM waves grouped?

↳ Wavelengths and frequencys

What is radiation dose?

↳ Risk of harm from exposure of radiation

What is the use of radio waves and what are the hazards?

↳ Tv+radio signals

↳ Can travel long distances through air

↳ Can bend around obstructions

↳ Penertrate the body

↳ Internal heating

What is the use of microwaves and what are the hazards?

↳ Sattelite communication + cooking food

↳Can reach stattelites

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

↳ Penertrate the body

↳ Internal heating

What is the use of infared waves and what are the hazards?

↳ Eletric heaters + cooking food + infared cameras

↳ Sensors can detect infared waves and turn them into an image as all hot objects emmit these waves

↳ Can transfer energy quickly to heat rooms and food

↳ Damage skin cells

What is the use of visible light waves and what are the hazards?

↳ Fibre optic communication

↳ Short wavelengths means visible light carries more information

↳ Can damage the retina

What is the use of UV waves and what are the hazards?

↳ Energy efficient lights + tanning beds

↳ Carries more energy then visible light

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

↳ Damage skin cells

↳ Skin ageing

↳ Increased risk of skin cancer

↳ Blindness

What is the use of X-ray waves and what are the hazards?

↳ Medical imagaing + treatments

↳ Pass easily through flesh but not denser eg-bone

↳ Kill cancer cells as it kills living cells

↳ Form of ionising radiation

↳ Damage/kill cells

↳ Cause mutations of genes

↳ Lead to cancers

What is the use of gamma ray waves and what are the hazards?

↳ Medical imagaing + treatments

↳ Pass easily through flesh but not denser eg-bone

↳ Kill cancer cells as it kills living cells

↳ Kill harmful bacteria

↳ Form of ionising radiation

↳ Damage/kill cells

↳ Cause mutations of genes

↳ Lead to cancers