misterteacher.com - Properties of Light

Properties of Light

Light Contents

> Main Idea
> Reflection
> Refraction
> Transmission

Students should be able to:

explain reflection, bending (refraction), and transmission of light.

Main Idea

When light hits a surface, the light can be reflected, refracted, transmitted or absorbed.

Reflection of Light

Light travels in straight lines called rays. When light bounces off of an object or a surface, it reflects. Light rays reflect from a surface according to the law of reflection: they always reflect at the same angle that they hit the surface.

Take a look at the mini-movie below. Click the flashlight to turn it on. Watch what happens when the light ray from the flashlight hits the surface of the mirror.

Use this mini-movie on your interactive whiteboard

The ray from the flashlight hits the shiny surface and reflects off it at the same angle. Your parents are able to see behind them when they are driving their car because of the law of reflection. They can see cars that are coming up behind because the light reflecting off of the car hits their rearview mirror at angle and then bounces to their eyes.

Rearview mirrors work because of the law of reflection.

Refraction of Light

When light rays enter a new medium at angle, it refracts, or bends. This happens because the speed that the light is traveling changes making the light change direction. You probably have seen refraction take place when you've been swimming. Objects on the bottom of the pool look different because light reflected off them changes direction when it leaves the water and begins traveling through air.

In science class you may have had the opportunity to shine light through something called a refraction block. The block is made of acrylic, which is similar to glass, and when light strikes the surface of the block at angle, it bends. The mini-movie below shows this in action.

Use this mini-movie on your interactive whiteboard

Notice that as the light leaves the refraction block, it bends again and travels at the same angle it was going before entering the refraction block. We see refraction in the real world all the time. Check out the examples below.

Refraction in the Real World


Rainbows are created when light shines through tiny drops of water. The drops refract the light, separating it into colors.	Magnifying lenses work when light is refracted as it passes through the lens.