Fireworks were invented in China thousands of years ago, and over the centuries they have been perfected to create wonderful light displays that are seen on many holidays, including the 4th of July, Chinese New Year, and New Year's Eve celebrations around the world. How are they made?

Gunpowder is the key ingredient, but as adjunct professor of chemistry John Conkling from Washington College in the US explains in this video, without chemistry, you wouldn't have burning mixtures and without these you simply can't have fireworks. 

Titanium gives a sparkling effect; strontium salts and lithium carbonate makes red; barium compounds are used to make green; sodium nitrate is needed to add yellow hues; magnesium or aluminium produce white light; blue is made out of copper compounds; and purple is a mix or strontium and copper.

Watch the video above to learn more about the chemistry of fireworks.

And, if you've ever wondered which is the largest single firework explosion in the world, just remember that every September the glorious 'Yonshakudama Shell' illuminates the sky of Ojiya City in Japan. Yonshakudama has a diameter of 1.2 metres and weighs a massive 420 kilograms.