Question

what do colligative properties depend on?
the type of dissolved particles.
the number of dissolved particles.
the change of dissolved particles.

Explanation:

Colligative properties (like boiling point elevation, freezing point depression) depend on the number of dissolved solute particles (molecules, ions), not their type or change. The type affects non - colligative properties, and "change" isn't a factor for colligative property dependence.

Answer:

The number of dissolved particles.