##### Explain how Archimedes checked the purity of gold crown?
Difficulty: Easy

Discoveries of Archimedes:

Archimedes was a Greek philosopher and mathematician and inventor of many war machines. Greek emperor gave him the task to determine whether his crown was made of pure gold or impure gold. Archimedes took the task and started thinking on it. He knew the volume of an object determines the volume of the liquid it displaces, when submerged in the liquid. One day when he was taking bath, he observed that more water overflowed the bath tank as he sank deeper into the water. He also noticed that he felt weightless as he submerged deeper in the bath tank. From these observations he concluded that the loss in weight is equal to the weight of water overflowed. Thinking this he at once designed an experiment in his mind to check the purity of the crown. He thought, he should weight the crown and equal weight of pure gold. Both should be dipped in the water into separate containers. Since every substance has different mass to volume ratio. If the crown was made of pure gold, it would displace same amount of water as an equal weight of pure gold. If the crown is impure, it would displace the different mass than the pure gold. Thinking this, he was so excited that he ran from the bath shouting “Eureka” which means I have found it. Like Archimedes discovery, science developed through observations and experiments rather than speculation alone.