1. Chemical Potential Energy
The breaking of bonds and they energy they produce

2. What is it?!
With a partner discuss what you think chemical potential energy is and where it comes from

3. Chemical Potential Energy comes from Chemical Reactions…
Atoms are rearranged
Bonds are broken/formed
The number and type of atoms at the beginning of the reaction are the same at the end

4. Brainstorm
With a partner write down as many examples as possible of chemical reactions that we see in every day life
Fire, wood, air bags, combustion in a car engine, explosives, eating, hot and cold packs, batteries

5. Where might we use chemical energy to store electrical energy?
Batteries! A battery is a device that is able to store electrical energy in the form of chemical energy, and convert that energy into electricity. Watch this!

6. What’s Really Happening in a battery?
In a electrochemical cell, chemical reactions of two different metals occur on the surface of the electrodes.
The reaction causes one electrode to become positively charged (cathode) and the other electrode to become negatively charged (anode).
The separation of these charges causes a electrical potential difference.
A battery is a connection of two or more cells.
A source is anything that supplies electrical energy

7. Understanding how a cell works
Read page 215 in the textbook and complete the How a Cell Works section of the notes using the ladder analogy
Complete this individually then explain what has happened to a partner. Finally, as a class go over what has occurred to create a electrical potential difference in a cell.

8. The electrodes are in contact with terminals in the cell
The electrodes are in contact with terminals in the cell. When the terminals are connected to an electrical pathway, electrons will flow.
The flow of electrons is always from the negative terminal to the positive terminal.
a unit of charge, called a coloumb, gains electrical potential energy when it passes through a source.
Electrical potential difference (voltage): measure of the electrical potential energy that is gained by a unit of charge. Measured in volts (V)
represents the amount of energy it took to carry the last unit of charge up the ladder
Electrical potential difference is determined by the nature of the chemical reaction in the cell

9. If you link together three 1.5 V cells what is the voltage?
If it took 1.5 units of energy to carry the last unit of charge up the ladder, then what is the electrical potential difference?
1.5 V
If you link together three 1.5 V cells what is the voltage?
4.5 V