Bridgeport High School junior T.J. Henry, 17, dropped a piece of Mentos candy into a bottle of soda and watched as the drink shot out to a height of almost 10 feet, like a geyser.
He ran away before he could get "sploshed."
Henry and about 500 other Bridgeport High students gathered outside the school before the lunch hour Tuesday to drop the candy into almost 600 bottles of soda.
Rosalinda Scott, the science teacher who helped coordinate the event, said the school holds an assembly every year to motivate students to perform better on the TAKS test.
"Everything was supposed to go off at the same time, but some students got a little anxious," Scott said.
Senior Jesse Grimes, 18, brought a bottle of soda and wasn't disappointed.
Some of the soda was still left in the bottle.
"I'm going to drink the rest of it during government class," Grimes said.