Question

What happens when a substance floats on top of water?

Answer 1

There are a few possibilities of which I can think right now.

Explanation:

This might be caused by: - The tension of the surface of water: Some objects float because they are in rest on the surface of the water, without braking this surface tension (it can literally be said that it is ON the water, not floating in it).
- The density of the object is smaller that that of water: Water has a density of `(1g)/(cm^3)`. If an object has a smaller density than this, it will float.
- Resulting density is smaller than that of water: Imagine you have a malleable steel ball. If you try to make it float, it won't. It will sink, as the natural density of steel is bigger than that of water. However, if you shape the ball into an object whose volume is large enough, the resulting effective density will be small enough (remember that `density = (mass) / (volume))`.
Hope it helps :D .