Question

A wooden block float and an iron block sink when both are placed on surface of water state reason

Answer 1

It is so because iron has more density than water and it sinks while as wood has lower density than water, that's why it floats

Answer 2

reason is density, wood has lower density and iron has high density as compare to water and the substance who has lower density is always float on the substance of higher density that's why wood float on water, you also seen the same condition in mixture of oil and water