If you have ever gone 'bobbing for apples,' you have witnessed a unique physical property of the fruit. Apples float in water because they are approximately 25% air by volume. This low density is due to the way the cells are structured with large intercellular spaces filled with air. This air content also contributes to the 'crunch' sound when you bite into one, as the air sacs rupture. While many other fruits like pears or oranges (without the peel) sink, the apple's internal 'pockets' make it buoyant. This structural design also makes apples excellent for baking, as the air spaces provide room for the fruit to soften without completely collapsing into a liquid mush.