31.During an elastic collision, kinetic energy is transferred without loss from one particle to another and the total kinetic energy remains constant. 32.A,B,C,E 33.Units of pressure include Pa, mm Hg, torr, atm, and bar. 34.16.34atm 35. A. 23kPa, B.0.25atm 36.temperature and kinetic energy are directly proportional to each other. For example, when temperature increases, the kinetic energy of the particles increases. 37.The average kinetic energy stays the same since the temperature of the water in the cups is the same as the water in the kettle. 38.STP stands for standard temperature and pressure. 39.Absolute zero is the temperature at which motion theoretically ceases. 40. 41.Intermolecular forces reduce the space between particles in a liquid. Therefore, liquid is a condensed state of matter and cannot be compressed with an increase in pressure. Gases are able to be compressed because there is empty space in between particles. This explains why liquids have a higher density than gases.