SCIENCE: UNIT 5 ☀️ LIGHT ☀️

SOURCES OF LIGHT

Light can come from a NATURAL SOURCE such as the Sun or lightning.

Light can come from an ARTIFICIAL SOURCE such as a candle or a torch.

PROPERTIES OF LIGHT

SPEED
Light is the fastest form of energy. It travels at 300 000 kilometres per second.

DIRECTION
Light travels in a straight line.

COLOUR
Light is made up of seven colours; the same colours we see in the rainbow.

MATERIALS AND LIGHT

TRANSPARENT MATERIALS
Light can pass through transparent materials.
We can see clearly through them.
Glass is transparent.

TRANSLUCENT MATERIALS
Some light can pass through translucent materials.
We can partially see through them.
Sunglasses are translucent.

OPAQUE MATERIALS
Light can't pass through opaque materials.
We cannot see through them.
Wood is opaque.

See more of examples of transparent, translucent and opaque objects here!

COLOURS

Sunlight is an example of white light.
White light is made up of seven colours.
We can see the colours of the light when light passes through a prism.

RAINBOW
When the Sun shines and it rains at the same time, we see a rainbow. This is because the raindrops are like tiny prisms that separate sunlight into seven colours:

- red
- orange
- yellow
- green
- blue
- indigo
- violet

PRIMARY COLOURS OF LIGHT
The primary colours of light are not the same as the primary colours of paint!

The primary colours of light are: RED, BLUE and GREEN.
If you mix the primary colours of light, you get WHITE.