Diet Coke
Diet Coke does not use a modified form of the Coca-Cola recipe, but instead an entirely different formula. The controversial New Coke, introduced in 1985, used a version of the Diet Coke recipe that contained high fructose corn syrup and had a slightly different balance of ingredients. In 2004, Coca-Cola introduced Coca-Cola C2, which it claims tastes much closer to Coca-Cola but contains half the carbohydrates. In 2005, the company introduced Coca-Cola Zero (replaced by "Coca-Cola Zero Sugar" in 2017), a sugar-free variation of regular Coca-Cola.
Diet Coke and Mentos eruption
A soda geyser (alternatively Diet Coke and Mentos geyser or Mentos eruption) is a reaction between the carbonated beverage Diet Coke and Mentos mints that causes the beverage to spray out of its container. The gas released by the candies creates an eruption that pushes most of the liquid up and out of the bottle. Lee Marek and "Marek's Kid Scientists" were the first to demonstrate the experiment on television in 1999. Steve Spangler's televised demonstration of the eruption in 2005 went viral on YouTube, launching a chain of several other Diet Coke and Mentos experiment viral videos.