Learners examine the method used to calculate the mass percent of an element in a compound. Three examples and one problem illustrate the method.

Students solve a molarity problem in a drag and drop exercise.

Learners examine graphs and read that the heat of fusion is the heat energy absorbed by one mole of solid as it is converted to liquid, while the heat of vaporization is the heat energy absorbed by one mole of liquid as it is converted to gas.

Students read brief descriptions of atoms, molecules, elements, and compounds, and complete a matching exercise that pictures these particles and molecules as pieces of taffy.