Grade 9 Science – Unit 4 – Electricity #1

Atom Structure

Electric Charges

Charging Electric Discharge

More Charging

1 1 1 1 1

2 2 2 2 2

3 3 3 3 3

4 4 4 4 4

5 5 5 5 5

All matter is composed of it.

What are Atoms?

They are negatively charged and they are found in orbits

circling around the nucleus of the atom

What are Electrons?

These are found in the nucleus of the atom. Their

charges are either positive or no charge.

What are Protons and Neutrons?

An object with an equal number of protons and

electrons.

What is a Neutral Object?

These subatomic particles move in space AND they can

be added or removed from the atom?

What are Electrons?

An object with more electrons than protons

What is a Negatively-Charged Object?

It is what objects with like charges do

What is Repel?

The force exerted by an object with an electric charge

What is Electric Force?

Objects with like charges repel each other and objects with opposite charges attract

each other

What is the Law of Electric Charges?

An imbalance of electric charges on

the surface of an object

What is Static Electricity?

Two different neutral materials are rubbed together

so that electric charges are transferred

What is Charging by Friction?

A list of materials arranged in order of their tendency to

gain electrons

What isthe Electrostatic Series?

Charging a neutral object by bringing another charged object close to – but not

touching – the neutral object

What is Charging by Induction?

Connecting an object to a large body that is capable of removing an electric charge

from an object

What is Grounding?

Charging an object by contact with a charged object

What is Charging by Conduction?

A large hollow sphere resting on the insulting cylinder, and

inside the cylinder, a belt stretched over two pulleys.

What is a Van de Graaff Generator?

These are placed on the roofs of tall buildings to provide a

safe path for lightning to follow to reach the ground

while not damaging the buildings

What isa Lightning Rod?

An electric discharge that occurs between clouds OR

between clouds and the ground

What is Lightning?

Rapid transfer of electric charge from one object to

another object

What is Electric Discharge?

There are an excess number of these

particles at the bottom of a thunder cloud

What are negatively-charged

water particles?

A material that lets electrons move easily

through it

What is a Conductor?

What isCharging by Conduction?

What is Charging by Friction?

A shift in the position of electrons in a neutral

object that occurs when a charged object is brought

near it

What is Induced Charge Separation?

A material that does not easily allow for the

movement of electrons through it

What are Insulators?