unit 5 ns5

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Page 1: Unit 5 ns5

HEAT AND LIGHT

Page 2: Unit 5 ns5

Thermal energy always travels from a hotter

object to a colder one. Some materials transfer

thermal energy easily. They are good

conductors. Materials that dont`t transfer

thermal energy easily are called insulators.

CONDUCTION

When two objects

are in contact,

thermal energy is

transferred from one

object to the other

CONVECTION

Thermal energy

travels through a gas

or a liquid by

convection.

RADIATION

Thermal energy can

be transferred

through space by

electromagnetic

waves.

Page 3: Unit 5 ns5

MELTING

Solid Liquid

EXPANSION

Materials expand when

receive thermal energy

EVAPORATION

Liquid Gas

CHEMICAL CHANGES

Thermal energy can cause

permanent changes(example: when we cook food)

Thermal energy causes changes in the state of

some materials

Page 4: Unit 5 ns5

Light is radiation that we can see with our eyes.

Light travels in straight lines.

Objects react to light in different ways:

Transparent

It doesn`t block

light

Translucent

It blocks some

light

Opaque

It blocks the light

completely

Page 5: Unit 5 ns5

REFLECTION

Some objects, like

mirrors, change the

direction of the light.

The mirrors reflect

the light.

REFRACTION

When light pass through

some transparent

substances (water) it

changes direction

slightly.