1. Electric Charge and Static Electricity!
6th Grade Module I – Motion, Forces and Energy
Unit 3 – Electricty and Magnetism
Lesson 1

2. Electric Charge
Property that leads to electromagnetic interactions between the particles that make up matter
Objects can have…
Positive charge (+)
Negative charge (-)
No charge (neutral)
Read and discuss p. 128 with diagram

3. Electric force
A force that two charged objects have on each other

5. How can an object become charged?
When the atoms gain or lose electrons. This can happen by…
1. Friction
Two objects are rubbed together. Electrons move from one object to another.
Ex. Rubbing a balloon on your hair, rubbing your shoes on the carpet in the winter
2. Contact
A charged object and an uncharged object touch. The charged object transfers some of its charge to the uncharged object.
Ex. Van de Graff Generator
3. Induction
A charged object is brought near an uncharged object (but doesn’t touch it). The electrons move around the object, depending on the charge of the charged object. (if you bring a negative object near an uncharged object, the electrons move away from the charged object)

6. Charging objects by FRICTION!
What is the charge on the hair?
Neutral
What is the charge on the comb?
(you do not need to write this down)

7. What is the charge on the hair?
Positive
What is the charge on the comb?
Negative
Why do the comb and the hair attract?
They are oppositely charged
How can we tell which one will be positive and which will be negative?

8. (you do not need to write this down)

9. Charging Objects by CONTACT -Van de Graaf generator

10. Charging Objects by CONTACT

11. Charging Objects by INDUCTION
You will see charging by CONTACT here, too. It’s also called by “conduction.”
Keep in mind that the electrons are moving.

12. Static Electricity Buildup of electric charge on an object
“Static” means not moving. The charge builds up until it moves somewhere else
Eventually leave as electric discharge
Ex: lightning
Brainpop – static electricity -

13. Examples? Conductors Insulators
Conductors
Insulators

14. Examples? Conductors Insulators Copper wood Silver plastic
Conductors
Insulators
Copper
wood
Silver
plastic
Other metals
rubber

15. Semiconductors Let SOME charge flow, but not as much as true conductor
Important for use in electronic devices
Ex: silicon

16. Electric Charges are Conserved! (you should write all this down)
Where do the positive charges on an object come from?
The protons in the atoms
Where do the negative charges on an object come from?
The electrons
How does a neutral object become negative?
By gaining electrons
Where might those electrons come from?
From another object that loses electrons
So, are the electrons ever really lost?
No!

17. Electric Charges are Conserved! (continued)
moving
Charging objects involves _________________ electrons
“The total amount of charge stays…
The same!”
The Law of Conservation of Charge