1236
"Halt, hands up!"
Take a small plastic cup from the medications, vitamins, and so on. N. Pour a little water in it, put any effervescent tablet and close the lid (nezavinchivayuscheysya).
Put it on the table, turning the "upside down", and wait. Gas, highlighted by the chemical reaction of water and tablets, will push the bottle, you will hear a "boom" and a bottle toss up.