history of electricity
Who was the early Greek philosopher who discovered that rubbed amber attracts small bits of dust?
Thales
According to the Law of Electric Charges, what do two "like" charges do when brought together?
They repel each other
What is the primary purpose of a device called an electroscope?
To test for the presence of a static charge
What is the term for the movement of electrons within a substance caused by a nearby charged object without direct contact?
Induction
What causes the sound of thunder during a lightning strike?
The rapid expansion of air around the discharge path.
Which physician to Queen Elizabeth I coined the term "Electric Effect" based on the Greek word for amber?
William Gilbert
What is the name of the process where two neutral objects are rubbed together and electrons are transferred?
Charging by friction
When a charged vinyl strip is brought near a neutral pith ball, why does the ball move toward the strip before touching it?
The charges in the strip cause the electrons in the pith ball to move (induction), creating an attraction between the strip and the ball.
What is "grounding," and what does it provide for electric charges?
It is the process of connecting a charged object to Earth's surface; it provides a path for charges to travel to or from the ground.
Is the ground (Earth) considered positive, negative, or neutral after a lightning strike?
Neutral (it is so large that it is not affected by the transfer of charge).
What were the two terms introduced by Benjamin Franklin to describe the two types of electric charges?
Positive and negative
During charging by friction, which specific subatomic particles are the only ones that move between objects?
Electrons
What happens to the leaves of a metal-leaf electroscope when a charged object is brought near the top (without touching)?
The leaves separate/repel because electrons move into or out of the leaves, giving both leaves the same charge.
When charging an object by induction, what is the relationship between the charge of the inducing object and the final charge of the neutral object?
The newly charged object will have the opposite charge of the charging object.
How far away from the actual rain can lightning potentially strike?
Up to 15 kilometers.
How did Benjamin Franklin prove that lightning is a form of static electricity?
He performed a dangerous kite experiment
If an acetate rod is rubbed with paper, what charge does the acetate acquire, and why?
The acetate becomes positive because it gives up electrons to the paper
Explain what happens to the charge of a pith ball once it actually touches a charged object.
Electrons jump between the strip and the ball, giving the ball the same charge as the strip, causing them to repel.
What is an "electrical discharge," and what is a common everyday example of it?
It is the very quick transfer of electric charges; common examples are sparks or shocks.
Explain how a lightning rod protects a building from damage during a storm.
It provides a point for the lightning to hit and a wire to direct the flow of electricity harmlessly down into the ground.
Why did William Gilbert use the word "electron" as the basis for the "Electric Effect"?
Because electron is the greek word for amber, the material thales originally used to observe static attraction
Using the Electrostatic Series, explain why rubbing sulphur with fur results in a negative charge for the sulphur.
Sulfur is lower on the electrostatic series than fur, meaning it has a stronger hold on electrons, meaning it grabs electrons from the fur
In a metal-leaf electroscope, why do the leaves stay slightly apart even after a charged strip that touched it is removed?
Because the electroscope has been "charged by contact," leaving it with a permanent net charge (either more protons than electrons or vice versa).
How is induction used in environmental applications to remove dust and particulate matter from industrial gas?
Gas is sent through pipes that charge the dust particles negatively; these particles are then attracted to and collected by positively charged plates.
Describe the multi-step process of how static electricity is used in a photocopier to make a copy of a document.
1. An electrostatic charge is placed on a drum.
2. Light from the original document neutralizes parts of the drum, leaving a charged "image."
3. Negatively charged toner sticks to the positively charged areas of the drum.
4. The toner is transferred to paper using heat and pressure.