Shadows

A shadow is made when an object blocks light. The object must be opaque or translucent to make a shadow. A transparent object will not make any shadow, as light will pass straight through it.

A shadow is made when an object blocks light. The shadow appears on the side of the object furthest from the light source.

The object must be opaque or translucent to make a shadow. A transparent object will not make any shadow, as light will pass straight through it.

Opaque objects make dark shadows. Translucent objects make faint shadows.

• If an object is moved closer to the light source, the shadow gets bigger.
• If an object is moved further away from the light source, the shadow gets smaller.

Transparent

Transparent materials let light pass through them in straight lines, so that you can see clearly through them. Glass is an example of a transparent material. 

Translucent

Translucent materials let some light through, but they scatter the light in all directions, so that you cannot see clearly through them. Tissue paper is an example of a translucentmaterial. 

Opaque

Opaque materials do not let any light pass through them. They block the light. Wood is an example of an opaque material. 


http://www.bbc.co.uk/schools/scienceclips/ages/7_8/light_shadows.shtml