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Unit 12: Alternative Energy Page 20 of 31
human ear can detect. Your crystal Energy from Molecular
radio detects in the AM band that Bonds
have been traveling from stations
(transmitters) thousands of miles We’re going to use electricity to
away. split the water molecule (H 2O) into
hydrogen and oxygen atoms.
After working with the Molecules can also be split
electromagnetic spectrum in Unit 9 chemically, or by getting hit by a
where we played with frequency fast-moving particle. When you
and wavelengths of light, you’ll find recombine the hydrogen and
that you’ve got all the basics for oxygen, energy is produced –
picking up AM radio stations using enough to power a small car.
simple equipment from Radio
Shack. If you guessed that this has to do
The radio is made up of a tuning with electricity and chemistry,
coil (magnet wire wrapped around you’re right! But you might wonder
a toilet paper tube), a detector how they work together. Back in
(germanium diode) and crystal 1800, William Nicholson and
earphones, and an antenna wire. Johann Ritter were the first ones to
split water into hydrogen and
One of the biggest challenges with oxygen using electrolysis. (Soon
detecting low-power radio waves is afterward, Ritter went on to figure
that there is no amplifier on the out electroplating.) They added
radio to boost the signal strength. energy in the form of an electric
You’ll soon figure out that you need current into a cup of water and
to find the quietest spot in your captured the bubbles forming into
house away from any transmitters two separate cups, one for
(and loud noises) that might hydrogen and other for oxygen.
interfere with the reception when
you build one of these. It takes energy to split
One of things you’ll have is to a water molecule. (On
figure out the best antenna length the flip side, when you
to produce the clearest, strongest combine oxygen and
radio signal in your crystal radio. hydrogen together, it makes water
and a puff of energy. That’s what a
fuel cell does.)
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