To arrange the objects by density from least dense to most dense, we can consider the typical densities of each:
- Leaf - Leaves are generally less dense than water, which is why they float.
- Water - The density of water is about 1 gram per cubic centimeter (g/cm³) at standard conditions.
- Rocks - Most common rocks, such as granite or basalt, have a density of around 2.5 to 3 g/cm³, making them denser than both the leaf and the water.
So, in order from least dense to most dense, the list is:
- Leaf
- Water
- Rocks