Charging by Contact

Question 1

What is LAW OF ELECTROSTATIC CHARGES (recap)

Answer 1

Opposite charges attract

Like charges repel

Charged and neutral objects attract

Question 2

What is Charging by Contact?

Answer 2

One object is already charged and one is neutral

The charged object makes contact with the neutral object

Electrons are dispersed evenly among the two objects

Question 3

What happens during Charging by Contact?

Answer 3

Produces two objects with the SAME charge

The original charged object becomes LESS charged because it lost a few electrons

Question 4

What happens during Charging by Contact? (NEGATIVELY CHARGED OBJECT)

Answer 4

Electrons go from negative object to neutral object after contact

Both objects are now negative
Original negative object is slightly less negative

Question 5

What happens during Charging by Contact? (POSITIVELY CHARGED OBJECT)

Answer 5

Protons cannot move…

But they CAN ATTRACT electrons from the neutral object so

Electrons go from neutral object to positive object after contact

Both objects are now positive
Original positive object is slightly less positive

Question 6

Example 1 - You’re getting up for school one morning, shuffling your feet along the wool carpet and touch the doorknob to the bathroom and get a shock. Explain why you received a shock. (Assume you are wearing cotton socks.)

Answer 6

Step 1: Getting Charged

Cotton below wool on elec. series
Electrons transfer from wool to cotton
Wool is positive
Cotton is negative

Step 2: Contact

Body is negatively charged
Doorknob is neutral
Electrons move from hand to doorknob
Both are negatively charged

Question 7

What is a METAL LEAF ELECTROSCOPE?

Answer 7

A device used to detect static charge

Leaves will separate if there is a charged object near it

Question 8

What is a PITH BALL ELECTROSCOPE?

Answer 8

A device used to detect static charge

Pith ball will react if there is a charged object near it