Here's why:

* Sugar Content: Orange juice contains a significant amount of dissolved sugar (sucrose). Sugar molecules are heavier than water molecules.

* Other Solutes: Orange juice also contains other dissolved substances like citric acid, vitamins, and minerals. These add to the overall mass of the juice.

Because of these factors, orange juice has a higher density than pure water. This is why orange juice sinks to the bottom when you pour it into a glass of water.