Manor Park First School - Knowledge Organiser

Science Focus: Understanding light and seeing Year: 3

(Key Vocabulary / Spellings)

pupil retina opaque translucent

transparent reflection reflect shadow

(Key Knowledge)

Look at sources, seeing, reflections and shadows.

Why do we need light? To see things.

What is dark? The absence of light.

What is a light source? A light source is something that makes its own light.

Common sources of light.

The Sun, the stars, flames, electric lights, some animals (fireflies and glow worms make their own light.)WARN children about dangers of looking directly at the sun. Explain ways we can protect our eyes.

Things you may think are light sources but aren’t.

The Moon, a mirror, shiny objects.These reflect light from a light source but are not light sources themselves.

How is a shadow formed?

A shadow is caused when light is blocked by an solid object. A shadow is larger when an object is closer to the light source. This is because it blocks more of the light.

How does the eye work?

The pupils control the amount of light entering the eye. The light hits the retina which changes it to nerve signals that get sent to the brain as an image.

Explain how light appears to travel in straight lines and how this affects seeing and shadows.

How does light travel? Light travels in straight lines. When it hits an object, it is reflected. If the reflected light hits our eyes, we can see the object. Some surfaces and materials reflect light well, other materials do not reflect light well.

Which surfaces reflect light best?

Surfaces that reflect light best are smooth, shiny and flat. Mirrors reflect so well they create a very clear image, although it appears in reverse.