Can a comb catch pepper?

Salt and pepper are mixed up on a plate. A plastic comb pulls the pepper out without touching it. The trick is to rub the comb first.

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You need

A dark plate (the salt shows up best on a dark one)
A little salt
A little ground black pepper
A plastic comb
A woolly sock or a wool cloth (or clean, dry hair)

Ask a grown-up to help. Ask a grown-up to help. Pepper stings in the eyes and makes you sneeze: do not blow on the plate or sniff it, and wash your hands afterwards. It works best on a dry day; if nothing happens, rub the comb again.

Try it

Put a little salt on the plate and a little ground pepper on top.
Mix them with one finger and spread the mix flat.
Hold the comb just above the plate. Nothing happens.
Rub the comb on the woolly sock about ten times, fast. (Combing clean, dry hair works too.)
Guess first: what will happen when the comb comes close?
Hold the comb about a finger-width above the mix and watch the pepper jump.

Why did it happen?

Rubbing the comb gives it a tiny electric charge that you cannot see. It is called static electricity. A charged comb pulls on small, light things. Pepper flakes are very light, so they jump up to the comb. Salt grains are heavier and stay on the plate, unless the comb comes very close.

New science word: static electricity. It means a tiny electric charge that builds up when two things are rubbed together.

Your challenge

Tear up some tiny bits of paper. Can your comb catch them too?