2. The Science of Batteries You will learn about: what’s inside a battery how a battery works how electricity moves the difference between current and voltage

3. First some background: everything is made of atoms – including this pencil No. 2 Wood magnified 10 times

4. The wood is made of cells Cells magnified 1000 times

5. Cells have parts inside them, like DNA DNA magnified 10,000,000 times

6. DNA and everything else are made of atoms O H Atoms C C H C C magnified 50,000,000 times

7. Atoms are made of a few parts: protons, electrons, and neutrons O H C C H C C P NP N N P E E E

8. The protons and neutrons are stuck together in the center of the atom; this center is called the nucleus. PNPNNP The basic parts of an atom EPN Neutron (0) Proton (+) Electron (-) There is a lot of space between electrons and the nucleus. The electrons spin around the outside of the nucleus. Key EEE

9. P NP N N P In fact, there is so much empty space between an atom’s electrons and nucleus that even this diagram is misleading EEE Really far apart!

10. To keep things simple, let’s use this diagram for an atom P N P N N P E E E

11. Sometimes Electrons Jump from One Atom to Another P N P NN PE P N P NN PEEE EE

12. What’s all this stuff about atoms have to do with batteries? Batteries make electrons jump from atom to atom to make things work

13. A mixture called an electrolyte (an acid or base) separates the carbon rod from the zinc layer A rod of carbon is in the center of the battery A layer of the metal zinc is around the outside of the battery The Basic Parts of a Battery

14. How a Battery Works + + + + + + + + + + + + + + - - -- -- - - - - - - - - - - - - - - - - - - - - - - - - - When the zinc reacts with the electrolyte, it steals electrons from the electrolyte and becomes negative When the carbon reacts with the electrolyte it loses electrons and becomes positive E If you connect a wire between the 2 metals, electrons flow from the negative zinc to the positive carbon

15. E E EEEEEE P N P N N P E E E P N P N N P E E E P N P N N P E E E P N P N N P E E E P N P N N P E E E P N P N N P E E E In the wire, electrons are jumping from atom to atom P N P N N P E E E P N P N N P E E E P N P N N P E E E P N P N N P E E E P N P N N P E E E P N P N N P E E E P N P N N P E E E P N P N N P E E E P N P N N P E E E P N P N N P E E E P N P N N P E E E P N P N N P E E E Close up of Wire E l e c t r i c i t y I S t h e f l o w o f e l e c t r o n s

16. Battery Power! + + + + + + + + + + + + + + - - -- -- - - - - - - - - - - - - - - - - - - - - - - - - - Put something on the wire, and the electrons get to work! E Batteries turn chemical energy into electrical energy !!

17. Not all batteries are the same One difference is how many electrons are moving. We call this current or amperage Another difference is how fast (or with how much pressure) the electrons are moving. We call this the voltage

18. Not all batteries have the same voltage 1.5 Volts9 Volts

19. E High Current/Amperage & High Voltage Low Current/Amperage & High Voltage Low Current/Amperage & Low Voltage High Current/Amperage & Low Voltage EEEEEEEEEEEEEEEEEEE

20. A 9 volt battery is just six 1.5 volt batteries combined together

21. Why Batteries Die + + + + + + + + + + + + + + - - -- -- - - - - - - - - - - - - - - - - - - - - - - - - - Batteries work because the metals react with the electrolyte. Batteries dies when its metals inside have completely reacted with the electrolyte. Either the metals have dissolved or the electrolyte has no more extra electrons to push around.