1What are electromagnetic waves?
transverse waves that travel at the same speed in a vacuum. they transfer energy from a source to observer
2Give examples of electromagnetic waves
Radio, micro, infra-red, visible, ultra-violet, x-ray, gamma
3What are the colours of the visible spectrum?
red, orange, yellow, green, blue, indigo, violet
4What's the electromagnetic spectrum?
from radio to gamma waves in order of decreasing in wavelength and increasing in frequency
5What can our eyes detect?
visible light but a limited range of frequencies of electromagnetic radiation
6What happens as the frequency of waves are increased?
Their potential danger increases too
7How are microwaves dangerous?
Internal heating of body cells
8How is infra-red dangerous?
Causes skin burns
9How is ultra-violet dangerous?
Damages cell surfaces and eyes leading to cancer and eye conditions
10How are x-rays and gamma rays dangerous?
Mutate and damage cells in the body
11What are radio waves used for?
Broadcasting, communications and satellite transmissions
12What are microwaves used for?
cooking, communications, satellite transmissions
13What is infra-red used for?
cooking, thermal imaging, short range communication, television remote controls and security systems
14What's visible light used for?
vision, photography and illumination
15What is ultraviolet used for?
security marking, sun beds, detecting fake money and disinfecting water
16What are x-rays used for?
observing internal structures, security and medical
17What are gamma rays used for?
Sterilising food and medical equipment, detecting and treating cancer
18How are radio waves produced?
By vibrations in electrical circuits
19What can changes in atoms and nuclei do?
Generate radiations over a wide frequency range, which is caused by absorption of a range of radiations - they produce electromagnetic radiation.