The video, posted to YouTube by The Periodic Table of Videos, shows a glass of the lemon-lime soda bubbling rapidly before changing colors from clear to green to a dark brown when mixed with metallic lithium.
“By the time I went to the lab, it looked like beer,” observes Sir Martyn Poliakoff, our host with the impressively wild white hair—sort of Albert Einstein meets Doc Brown. The experiment comes from the latest episode of The Periodic Table of Videos from the chemists at the University of Nottingham in England. This particular entry was inspired by the fact that 7-Up really did contain lithium.
When a piece of metallic lithium was added to the drink it began to heat up, bubble, and change color. Poliakoff went on to explain how he and his team attempted to figure out exactly what caused the reaction, and exactly what in the soda caused the changes.
As Poliakoff explains, the experiment began essentially as a joke because 7Up used to contain lithium salts.