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Electromagnetic Waves - What are Microwaves?
Microwaves are part of the electromagnetic
spectrum.
Microwaves have wavelengths
that are shorter than radio
waves.
How are Microwaves Used for Communication?
Microwaves have some wavelengths
that pass easily through
the atmosphere and they are used to transmit information
to satellites.
Satellite TV
and mobile phone
(or smartphone)
networks use microwaves. Some people have concerns
that microwaves from mobile
phones
may be harmful.
However, the intensity
of the microwaves emitted from
mobile
phones is low
and the evidence for their safety
is not conclusive.
How are Microwaves Used for Cooking?
Some
microwaves have wavelengths
that are absorbed by
water
molecules.
Microwave cookers use
waves which
give energy
to the water
molecules in food, causing the food
to get hot.
The cooker has a metal
door screen and outer
case which
absorb or reflect
microwaves to protect people who use the cooker.
How can Microwaves cause Harm?
Living cells can absorb microwaves.
The cells
may
be damaged or killed by
the
heating effect of the waves.
Skin cells can be burned.
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