What happens when you mix jello with water?

When you mix jello with water and let it sit, the jello powder will absorb the water and begin to dissolve. As sugar molecules and other small particles become surrounded by water molecules, the water begins to get trapped within the structure of the jello powder, causing it to hydrate. This process causes the mixture to thicken and become more viscous as the jello powder absorbs more and more water. Finally, the mixture will reach a point of maximum hydration where the jello powder has absorbed all the available water and forms the iconic jiggly texture of jello.