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Glass

What is glass?
Glass is a hard solid material but it is brittle and is usually transparent, translucent, see through.  

How is glass made?
Essentially, Glass is made by heating up ordinary sand that you find on the beach to very high temperatures, around 1700°C (3090°F) where it melts and becomes liquid sand so to speak. When the liquid sand cools, it doesn’t return its original state as sand. It becomes what science calls an amorphous solid which is like a frozen molten liquid and is a mix of solid (some crystalline order) and liquid (some molecular randomness). It doesn’t matter how much it cools, it never quite sets as a solid.  

As far as manufacturing the glass we see around us everyday, sand is mixed with limestone (calcium carbonate) and soda ash (sodium carbonate) and melted together. Glass collected from recycling such as bottles can also be included at this stage. 

This results in what is known as soda-lime-silica glass which is the glass we see all around us in bottles, jars windows etc.

What is glass used for?
  • Glass windows 
  • Glass bottles
  • Light bulbs
  • Reading glasses
  • Cups
  • Mirrors
  • Shower screens
  • Glass tiles
  • Containers
  • Cooking products
  • Plates
  • Science products such as magnifying glasses

Why is glass so popular?
  • When heated, it is easy to shape into whatever we need
  • It is chemically inert meaning it doesn’t react with anything that comes into contact with it which means it’s perfect for use as jars or bottles to store food and liquids in.   
  • The process of making glass is relatively cheap and inexpensive. 
  • It can be recycled as it is like our glass milk bottles once were or melted down and made into something else again and again.