In the solution that bathes our neuron, most of the floating atoms and
molecules are charged. That makes these particles ions.
Now charges interact with each other. The animation below illustrates the
interaction of opposite charges (one positive and one negative).
Figure 4. When two opposite
charges are near each other they will be drawn towards each other. That
is, as far as ions are concerned, opposites attract. That is the principle
that drives electricity through electrical lines. An example would be a
circuit with a battery. The lines ultimately connect at the two poles of
the battery: one labeled positive and one labeled negative.
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