Some people tap on the soda can to avoid a spray of soda from the can that has just been shaken up. When the can is shaken up, some of the carbon dioxide gas comes out of the liquid solution. The gas bubbles are stuck to the side, top and bottom of the can, in addition to forcing the liquid out which is blocking its path. Tapping on the can dislodges and breaks the bubbles. When the can is opened, only the gas escapes instead of the soda shooting out!
Why do people tap on soda cans before they open them?
