How Pop Rocks hold gas inside candy
Pop Rocks are made by trapping carbon dioxide—the same gas that gives soda its fizz—inside hard candy while the candy is under pressure. When saliva dissolves the sugar, those tiny pockets break open and release the gas, producing the crackling sensation. Soda’s bubbles come from carbon dioxide dissolved in the drink; pouring, swallowing, and warming it help the gas escape.
Why the mixture can make you burp
Swallowing either fizzy candy or soda can send some gas into the stomach. As gas builds up, it stretches the stomach slightly and may prompt a burp: the upper opening of the stomach briefly relaxes, letting gas travel back up the esophagus and out through the mouth. Combining the two can make that release more noticeable, but it does not create a reaction that makes the stomach burst.
The memorable part is the sound, not a dangerous chemical event: the stomach is simply venting gas from two carbonated treats.
