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Unit 8: Chemistry Page 20
experiment, you’ll need to omit the of energy. That’s what a fuel cell
water, as it’s already included in does.) Back to splitting the water
the bottle). molecule - as the electricity zips
through your wires, the water
Electrochemistry molecule breaks apart into smaller
pieces: hydrogen ions (positively
If you guessed charged hydrogen) and oxygen
that this has to ions (negatively charged oxygen).
do with Remember that a battery has a
electricity and plus and a minus charge to it, and
chemistry, that positive and negative attract
you’re right! each other.
But you might wonder how they
work together. Back in 1800, So, the positive hydrogen ions zip
William Nicholson and Johann over to the negative terminal and
Ritter were the first ones to split form tiny bubbles right on the wire.
water into hydrogen and oxygen Same thing happens on the
using electrolysis. (Soon positive battery wire. After a bit of
afterwards, Ritter went on to figure time, the ions form a larger gas
out electroplating.) They added bubble. If you stick a cup over
energy in the form of an electric each wire, you can capture the
current into a cup of water and bubbles and when you’re ready,
captured the bubbles forming into ignite each to verify which is
two separate cups, one for which.
hydrogen and other for oxygen.
But how did they know which
bubbles were which? You can tell
the difference between the two by
the way they ignite (don’t’ worry –
you’re only making a tiny bit of
each one, so this experiment is
completely safe to do with a grown
up).
It takes energy to split a water
molecule. (On the flip side, when
you combine oxygen and hydrogen
together, it makes water and a puff
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