Light
1) Light is a form of energy.
2) Light must be present for us to see. Without light, we cannot see. Thus we cannot see in the dark.
3) Objects that give off light are known as sources of light. There are two types, natural and artificial sources of light.
4) The Sun is our main source of light during the day.
5) The moon is not a source of light.
6) The moon looks bright at night because it reflects light from the Sun.
7) We can see sources of light because they give off light.
8) We can see objects that do not give off light when there is light shining on them. The light is then reflected from the object and enters our eyes.
9) We can see through an object clearly if it allows most of the light to pass through it. It is a transparent material.
10) We cannot see an object clearly if it allows only some light to pass through it. It is a translucent material.
11) We cannot see through an object at all if it does not allow any light to pass through it. It is known as an opaque material.
12) A shadow is formed when light is blocked by an opaque object.
2) Light must be present for us to see. Without light, we cannot see. Thus we cannot see in the dark.
3) Objects that give off light are known as sources of light. There are two types, natural and artificial sources of light.
4) The Sun is our main source of light during the day.
5) The moon is not a source of light.
6) The moon looks bright at night because it reflects light from the Sun.
7) We can see sources of light because they give off light.
8) We can see objects that do not give off light when there is light shining on them. The light is then reflected from the object and enters our eyes.
9) We can see through an object clearly if it allows most of the light to pass through it. It is a transparent material.
10) We cannot see an object clearly if it allows only some light to pass through it. It is a translucent material.
11) We cannot see through an object at all if it does not allow any light to pass through it. It is known as an opaque material.
12) A shadow is formed when light is blocked by an opaque object.
SHADOW
- Refer to concept map on light and shadows
(I) How to make a shadow bigger
(II) How to make a shadow smaller
(III) What is sharpness?
(IV) What affects the shapes of shadows?
When drawing light paths, please use rulers and make sure the light paths touch the objects and eyes and when necessary they meet at the same point.
For shadows, pls colour the shadows with pencil.
Please remember the KEY words BIG & BLUR and SMALL & SHARP for shadows.
Please refer to pages 26 and 27 of your textbook for a summary of both chapters on Light and Heat.
