1. Electricity

2. Electron: negatively charged fundamental particle
Recall
Electron: negatively charged fundamental particle
Proton: positively charged fundamental particle
Static electricity: build up of charge
Electricity: flow of electrons

3. Electrons and the Greeks
The ancient Greeks noticed that rubbing amber could cause it to attract bits of straw
The name we use for this type of attraction, electricity, comes from the Greek word for amber, electron

4. Key concepts about charge
There are two electrical charges:
–and+
Electrons have a - charge and are free to move in and between certain types of materials
Protons have a + charge and cannot move
The flow of electrons is called electricity

5. Most objects are neutral, because they have an equal number of + and – charges/electrons
When 2 neutral objects are rubbed together they each get an opposite charge

6. The Law of Electric Charges says that opposite charges attract, like charges repel
+ and – charged objects also attract most neutral objects

7. Attract: cling together
Repel: push apart
Amber: yellow-orange
fossilized tree resin -
often containing insects

8. ? Attraction What is the charge on the mystery box?
The object could be neutral or positive

9. ? Attraction What is the charge on the mystery box?
The object could be neutral or negative

10. Repulsion ?
What is the charge on the mystery box?
It MUST be positive

11. Repulsion ?
What is the charge on the mystery box?
It MUST be negative

12. + What is the charge on the pith ball? What happens when we
bring a charged rod near?

13. Electroscopes A device that can detect the charge on an object
Examples: Metal Leaf Electroscope

14. Your Turn Read and make a small note on Page 471
page 470 on Electrostatic Paint Sprayers
Page 471
Q: 4-7