Why do some objects float on the water ? And some sink ?

Explanation

1. Floating of sinking of objects on water depends on two factors.
a. Relative density
b. Weight of the water displace by the object
2. If the relative density of an object is greater than 1, the object sinks otherwise it floats.
3. Eventhough the relative density is greater than 1. the weight of the water of displaced by the object equal to the weight of the object itself, the floats on the water.