Consider the molecules H2O, H2S, H2Se, and H2Te. Which do you expect to have the highest boiling point, and why? H2O, because it experiences hydrogen bonding.
H2S, because it dissociates and forms ions.
H2Se, because it experiences ion-dipole forces.
H2Te, because it has the most electrons to form a dipole.

Which of the following statements is true? a. most heat energy is easily recovered and used for useful actions. b. friction causes molecules to vibrate more slowly. burning air and gasoline in an c. engine changes chemical energy into mechanical energy. it is impossible to d. change mechanical energy into mechanical energy.