4. By 1800 he had developed the so-
called voltaic pile, a forerunner of the
electric battery, which produced a
steady stream of electricity
5. Volta piled up
silver and zinc
disks with cloths
between them
that had been
soaked in salt
water.
6. The salt water causes a chemical
reaction in the molecules of the
metal.
7. The silver loses some of its
electrons, making it have a positive
charge.
8. The zinc gains extra electrons,
making it have a negative charge.
9. Remember that atoms like to have
a balance of protons (+) and
electrons (-).
3 electrons 3 protons
10. So, the extra zinc electrons flow to
the silver atoms, which don’t have
enough electrons. Remember that
electricity is the flow of electrons.
11. When all of the extra zinc electrons
have found a silver atom that
needs them, the battery is dead.
12. Now, you will build a voltaic pile.
However, instead of silver, you will
use copper and instead of zinc, you
will use aluminum. It will achieve
the same reaction.