becuase if there is no soda in bottle it gives gravity but if there is a soda in bottle it will sank becuase it is heavy and the water can no longer to give it a gravity. maybe I'm wrong
The difference in the amount of dissolved sweeteners leads to a difference in density. Cans of regular soda tend to be more dense than water, so they sink. Cans of diet soda are usually less dense than water, so they float.
