What could you do to change what would sink and what would float in water? Like, how would you change the density of water to make things that would sink, float?

Let’s say you have a penny and a container of water. Every time you put the penny in the water, it sinks. If you would want to make it float, you would need the wait to spread out. Obviously you can’t do that with a penny, you would have to put the penny on something else like a bar of soap. You would put the penny on top and it should float because without anything the soap already floats.

Comment down below if that is what you wanted, the question is kind of complicated.