Question

which metal floats on water and why ?

Answer 1

Sodium, potassium and lithium are the metals which can float on water because they are less dense than pure water.
Also, being highly reactive, these metals react with water and burn or explode.

Hope helped....

Answer 2

lithium, sodium,potassium etc metals floated on water because these metal reacts react with water (h20) to form hydrogen gas which helps them to float.