ELECTRICITYChapter 16

Lesson One Vocabulary Electricity- a form of energy produced by

moving electrons

Electromagnet- a magnet made by coiling a wire around a piece of iron and running electric current through the wire

Electricity: Lesson One In an atom, electrons

move around the nucleus.

Electrons can also move from one atom to another.

This movement of electrons produces electricity.

Electricity: Lesson One Electricity- or electric energy, is a form of

energy produced by moving electrons. Electricity can produce light energy, sound

energy, heat energy, or mechanical energy.

Electricity: Lesson One An electromagnet is a

magnet that uses electricity.

It is made by coiling wire around a piece of iron.

An electric current runs through the wire and onto the iron.

Electromagnets are different from regular magnets because they can be turned on and off.

Electricity: Lesson One Electricity makes the fan of a

motor move. An electric motor has a coil

wire that can spin inside a magnet.

When the motor is on, electricity produces a magnetic field in the wire.

The coil becomes an electromagnet and spins because its poles are attracted to and repelled by the permanent magnet.

This spinning causes the blades of the fan to spin!

Lesson 2 Vocabulary Static electricity- the buildup of charges on an

object Electric current- the flow of electrons Current electricity- a kind of kinetic energy that

flows as an electric current Conductor- a material that carries electricity Insulator- material that does NOT conduct

electricity well

Electricity: Lesson Two Did you ever touch a doorknob

and get a shock? If so, you have felt static

electricity. Static electricity is the buildup

of charges on an object. Most objects have no charge. But when one object rubs up

against another, electrons move from one object to the other.

The objects then become charged.

Opposite charges then attract each other.

Electricity: Lesson 2 When objects with

opposite charges get close, electrons jump from one object to the other.

The shock you felt when you touched the doorknob was caused by electrons moving.

The sparks are called static discharge.

The crackling noise is the sound of the sparks.

Electricity: Lesson 2 Lightning is also static

discharge. Negative charges collect

at the bottom of clouds. When charges jump from

the cloud to the ground, you see lightning.

Lightning is a dangerous static discharge and can cause a fire.

Electricity: Lesson 2 Static electricity is

potential energy but changes to kinetic energy when it discharges.

That kinetic energy can then turn into light, heat, or sound energy.

Static energy releases energy for just a short amount of time.

Electricity: Lesson 2 For electricity to be useful,

there must be a steady source of electricity.

Current electricity can provide a steady source of electricity.

If electrons have a path to follow, they will keep moving instead of building up a static charge.

This movement is called electric current.

Electricity that flows in this way is kinetic energy called current electricity.

Electricity: Lesson 2 Electricity can be used for

all sorts of appliances in your home.

The amount of electric energy an appliance uses is measured in watts.

For example: A hair dryer uses 1,600 watts and a clothes washer uses only 400 watts.

Electricity: Lesson 2 Electricity moves easily

through conductors. Most metals are good

conductors and copper is the metal commonly used for conducting electricity.

An insulator does not conduct electricity well.

We use insulators to protect people from electric current.

Lesson 3 vocabulary Electric current- the PATH an electric

current follows Series circuit- an electric circuit in which

the current has only one path to follow Parallel circuit- an electric circuit that has

more than one path for the current to follow

Electricity: Lesson 3 An electric circuit is the

path that an electric current follows.

The circuit needs a source for the current (like a battery).

A circuit can also have a switch.

When the switch is off, there is a break in the circuit and this stops the flow of the current.

Electricity: Lesson 3 A series circuit is one type of

electrical circuit. In a series circuit, the current

has only one path to follow. All the parts of the circuit are

connected to a single path. If any part of the path is

broken, the current stops flowing.

If one part of a series circuit stops working, everything in the circuit stops working.

Electricity: Lesson 3 A parallel circuit has more

than path to follow. Each part of the circuit has

its own path. In a parallel circuit, one

part can be turned off, and all the other parts can stay on.

For this reason, a parallel circuit is more useful than a series circuit.

Electricity: Lesson 3 Some circuits are simple

and others are not. When engineers work on

a design for a new machine, they draw a wiring diagram.

The diagram uses symbols.

Do you know the symbol for battery, switch, and light?