The condensation temperature of a material is the temperature at which the material makes a transition between being a vapor and being a solid. Three of the most important materials in the early solar nebula were water vapor, iron, and hydrogen. Arrange these three materials in order of condensation temperature, from highest to lowest.

From highest to lowest, we have Iron> water> hydrogen

Explanation: Condensation temperature is temperature at which materials transit from being a vapor to being a solid.The early solar nebula consisted of water, iron and hydrogen, and the temperature in the nebula is said to decrease with distance away from the proto-sun, with heavy elements such as iron whose distance is nearer to the protosun,  will have a  higher condensation temperature as compared to light elements, such as hydrogen  which have lower  temperature since gases are further from the sun. water vapour is heavier than hydrogen and therefore will have a higher condensation temperature than hydrogen.