1. The longest electromagnetic waves Microwaves and radio waves

2. Microwaves Gamma raysX-raysultraviolet Visible light infraredmicrowavesradio waves Microwaves are longer waves than infrared waves We cannot see or feel microwaves but we have lots of uses for them!

3. What use are microwaves? A microwave oven uses microwaves to cook and reheat food This works because the microwaves make the water molecules in the food vibrate and get hot.

4. More about microwaves Microwaves are used for communicating – many television signals are sent by microwaves Mobile telephones use microwaves to transmit their messages. Microwaves easily pass through the atmosphere or through space. Satellites can collect and send news, information and pictures from around the World!

5. Radio waves The first radio waves were used in 1901 by Marconi to send a message across the Atlantic Radio waves are used all over the World – each radio broadcast that is received travels using a slightly different wavelength Radio receivers can be ‘tuned in’ to receive long wave, medium wave, shortwave radio waves

6. How are different radio wavelengths useful? Short wave radio signals travel in straight lines over fairly small distances Short wave radio waves are used for TV and FM radio broadcasts Walkie talkie, police and ambulance radios use short waves

7. Long radio waves Long wave radio waves can curve around the Earth so can travel long distances. On holiday you might be able to pick up broadcasts from home by tuning a radio in to a long wave radio station

8. Time to test what you know! Click the link to test yourself..or go back to look at the presentation again…..