P12 Flashcards
What is the electronmagnetic spectrum made up of
- radio waves
- micro waves
- infrared radiation
- visible light
- ultraviolent waves
- x rays
What is the wavelength of visible light ?
350 nm to 650 nm
What do electromagnetic waves do
Transfer energy from a source to an absorer
What do white light contain
All the colours of the visible spectrum
What is infared radiation used for
Carrying signals from remote control handsets and inside optical fibres
What are microwaves used for
Used to carry satellite tv programmes and mobile calls
Why are microwave sand radio waves dangerous
Can heat the internal parts of people’s bodies
Why are infared radiation dangerous
Can cause skin burn
What are gamma rays used to do
To kill harmful bacteria in food and to kill cancer cells
What does ionising radiation do to atoms
Makes uncharged atoms become charged
2 reasons why x rays are used in hospitals
- to make images of your internal body parts
- to destroy tumours at or near the body surface
