A large ship can float but a steel needle sinks because of

A ship made of iron can float in water but an iron needle sinks. Why ?

Suppose we have an iron nail and an iron ball of same mass. When submerged in water, the iron ball may float but the nail alway sinks. This is because

How is an iron ship able to float where as an iron needle sinks?

A piece of nail sinks in water but a boat floats in it because

A needle can float on clear water but sinks when some detergent is added to it. This happens because