When a solid (solute) is dissolved in a liquid (solvent), they form a solution.

In a solution, the solute seems to disappear. In reality, the solute is broken down into such small particles that they are invisible. If the solvent is removed by boiling or evaporation, then the solute particles join together again to form crystals.

When sugar is dissolved in water, the sugar particles spread evenly

throughout the water to form a sugar solution.

However, the sugar particles remain sugar particles and the water particles remain water particles — a physical change has occurred.

If the water is boiled off or left to evaporate, then sugar crystals are left behind.

The solute and solvent particles stay the same, they're just mixed together.

Characteristics of a solution:

• Uniform (homogenous)

• Doesn't change over time or settle

• Particles are so small they can't be separated by filtering

• Cannot see different particles

• It doesn't scatter a beam of light (Tyndall Effect)
  

Tyndall Effect

Is there a limit?

Saturation is the word used when a liquid (solvent) cannot dissolve anymore of the substance (solute).

The solution is so highly concentrated (packed with solute particles) that no more of the solute can be dissolved.

Saturation point changes for each solute.