My friend put a little salt (the coarse variety) on the table, and then mixed some pepper in it. He asked me if I could separate the two.
I said it was impossible. He rubbed a plastic spoon with a piece of woollen cloth, and held it an inch or so above the mixture. The pepper jumped up to the spoon and stuck to it. In this way, he separated the pepper from the mixture.
Why did this happen?
The spoon had got negatively charged when he rubbed it with the wool. When my friend held it above the mixture, both the pepper and the salt were attracted to it, as they were uncharged bodies. The pepper being lighter flew up and got stuck to the spoon. If he had further lowered the spoon the salt too would have been pulled up to it.
Picture Credit : Google
