Glass is made from sand or silica, mixed with a some other chemicals to make it stronger or give it colour.

Glass is unreactive, waterproof and usually transparent, making glass ideal for holding liquids, so is used for beakers and science experiments!

Glass is brittle, which means it breaks into pieces if it hits something.
Can you think of how you might strengthen glass?

Refraction happens when light speeds up or slows down when it travels through a different substance.
Any type of light source can be used to show refraction. The laws of refraction were first discovered by Persian physicist Ibn Sahl in 984.
Mirrors use reflection, not refraction.

All glass is recyclable. It takes much more energy to make new glass than to recycle glass.

First the glass is collected by your local council recycling service, then it is sorted from other materials and sent to a glass recycling plant. There it is chipped up into glass fragments called cullet, sorted using light into different colours and then sent off to be melted and formed into new bottles or jars.

Even better than recycling glass is reusing it first. Maybe you could use it as storage, or make jam or chutney and put it in old jars. Glass can be upcycled into lovely chandelier style lampshades or pretty vases. The ideas are as endless and creative as your imagination!