1. Cells and Batteries

2. Electricity & Circuits
Electricity: the presence and flow of __________ ____________, usually in the form of ____________ through ______________ such as copper wires. Electric Circuit: closed path along which ____________ that are powered by an energy source can flow.
A circuit requires a source of electrical energy which is often a cell or battery.

3. A battery is more than one cell connected.
Battery vs. Cell
The word ‘battery’ is used when in actuality, you’re referring to a ‘cell.’
A cell is a device that uses chemical reactions to produce a _________ of electrons.
A battery is more than one cell connected.
Electric Cells are usually made by separating 2 DIFFERENT metals and putting a liquid that can conduct electricity between them.

4. Voltaic Cells
Voltaic Cell (cell): a source of ________ that generates an electric _________ by chemical reactions involving two different __________ or metal compounds separated by a solution that is a ____________. Electric Current: a flow of electric charge.
Look familiar?
Voltaic Cells are the popular AA and D “batteries”.
A battery is made when you place two or more cells in a flashlight.

5. Parts of a Cell
Electrolyte: a ____________ or ___________ that conducts charge.
In this example, lemons contain acids; acids ______________ electricity well.
Electrodes: the metal terminals in a cell or battery.
Must be ______________ metals with different abilities to ___________ electrons.
In this example, the two electrodes are made of aluminum and copper.

6. First – What is an ion?
Ion: an atom in which the total number of electrons is not equal to the total number of protons, giving the atom or molecule a net ______________ or _____________ electrical charge. 
Ions can be created, by either chemical or physical means, via ionization.
Practice:
1. An oxygen atom, chemical symbol O, gains two electrons. What is its new atomic symbol?
2. A magnesium atom, chemical symbol Mg, loses one electron. What is its new atomic symbol?
3. A nitrogen atom, chemical symbol N, gains three electrons. What is its new atomic symbol?
_____

7. How Voltaic Cells Work Al
In a voltaic cell, chemical reactions take place at the surface of each ____________ in contact with the __________________.
The chemical reactions depend on the metals that are used, but the operation of every cell involves the movement of _______________ and ________.
HOW THIS CELL WORKS:
Aluminum atoms give up three electrons to the connecting wires, forming Al3+ ions.
The Al3+ ions leave the aluminum electrode, entering the electrolyte solution. This causes the electrode to slowly degrade.
The electrons flow from the aluminum electrode (weak electron affinity) to the copper electrode (strong electron affinity).
The flow of electrons through the light give it energy to light up.
5) At the copper electrode, hydrogen ions(H+) from the electrolyte combine with the electrons, forming hydrogen gas bubbles. e- e- e- e- H+ Al H2
Electrode: Copper
Electrode: Aluminum
Al3+
Electrolyte