# What happens when a substance floats on top of water?

- The density of the object is smaller that that of water: Water has a density of $\frac{1 g}{c {m}^{3}}$. 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)).