A scientist needs to calculate the amount of heat released when a sample of melted iron freezes. Which constant should be used? –DHvap DHvap –DHfus DHfus.

How does water evaporating from a glass show that matter is made up of particles? a. the heat energy from the air causes the glass to fill up with water particles. b. the liquid water particles turn into water vapor that spreads in the air. c. the particles of the glass dissolve in water and cause it to evaporate. d. the tiny particles of the glass evaporate and seem to disappear.