Question

an iceberg float on water why

Answer 1

icebergs actually contain a lot of air. Far from being the solid blocks of ice many people imagine, icebergs are riddled with billions of tiny, trapped air bubbles, giving the huge bergs their white appearance.

Answer 2

because an iceberg don't float on water. that is a piece of ice whose size larger than the length of the water body

or
the ice Berg floats because slowly it gets converted into water