Transcript 8.1 Electric Potential Energy and Voltage

8.1 ELECTRIC POTENTIAL ENERGY
AND VOLTAGE
BC Science 9:
p. 270-279
Energy
• Energy is the ability to do
work or to make things
move or change.
• Energy can be stored in
electric charges within
batteries so that it can be
used later to do work.
Electrochemical Cells
• Electrochemical cells convert chemical
energy into electrical energy.
• Connecting electrochemical cells
together creates batteries.
• The ends of the batteries are known as
terminals.
– Connecting the terminals allows electrons
to flow from the battery through a device
that converts electric energy into different
forms of energy (ie. heat, light, sound).
Electrochemical Cells
• A battery provides energy to push negative
charges (ie. electrons) through conductors.
• A battery has two terminals called electrodes.
– One terminal is positively charged the other is
negatively charged.
Electrochemical Cells
• A battery’s electrochemical cells
can be wet cells or dry cells.
– In dry cells, the electrolyte is a
moist paste.
– In wet cells, the electrolyte is a
fluid.
• Electrons build up at one
terminal, leaving it negatively
charged and are withdrawn from
the other terminal leaving it
positively charged.
Electrochemical Cells
Electric Potential Energy
• Electric energy can do work.
• Electric energy that is stored is potential
energy.
• When energy is moving, it is known as kinetic
energy.
• The amount of electric potential energy per
coulomb of charge is called the potential
difference (ie. voltage).
• Extra electrons will move to a location where
there are less of them.
Producing Voltage
• Electrodes in an
electrolyte chemically
react to produce electrons.
• Different charges are
created on each electrode.
• This difference in charge
is called potential
difference (ie. voltage).
Measuring Voltage
• Voltage is measured in
volts (V).
• A voltmeter is a device
that measures the amount
of potential difference (ie.
voltage) between two
locations of charge
separation.