Why the Diet Coke floats?

Diet Coke floats because its density is slightly less than the density of regular Coke. This is because diet Coke contains aspartame, an artificial sweetener that is less dense than sugar.

The density of an object is defined as its mass per unit volume. In other words, density is a measure of how much "stuff" is packed into a given amount of space.

The more "stuff" (mass) there is in a given volume, the denser the object.

The density of regular Coke is approximately 1.02 g/mL (grams per milliliter). This means that 1 milliliter of regular Coke has a mass of 1.02 grams. The density of diet Coke is approximately 0.99 g/mL. This means that 1 milliliter of diet Coke has a mass of 0.99 grams.

Because diet Coke has a lower density than regular Coke, it is less dense and will therefore float on regular Coke.