Question

Concept of density how is it possible that certain bowling balls float

Answer 1

Some bowling bowls can float because the density of the ball (mass per volume) is less than the density of water. The density of water is approx. 1g/mL. So if the bowling ball's density is less than 1 g/mL, it will most likely float.

Answer 2

If it is floating in water, it must be a very non-dense bowling ball. If it is floating in other liquids, that may mean that the liquid is more dense than the ball. If the ball is less dense, it will float. If it is more dense, it will sink. Just like how oil floats on water, the oil is less dense than water.