You'll see raisins bobbing up and down in the soda. Why does this happen? Raisins are denser than the liquid in the soda, so at first, they sink to the bottom of the glass. The carbonated soda releases carbon dioxide bubbles. When these bubbles stick to the rough surface of a raisin, the raisin is lifted because of the increase in buoyancy. When the raisin reaches the surface, the bubbles pop, and the carbon dioxide gas escapes into the air. This causes the raisin to lose buoyancy and sink. Then the process happens over and over again until the soda loose its carbon dioxide gases.
