We discussed earlier some basic principles about the behavior of gases called the kinetic-molecular theory. Among other things, this theory suggests that gas molecules are in constant motion, and the average speed of the individual gas particles is dependent upon temperature – the higher the temperature, the faster the molecules move. It is not just gas particles that are in constant motion. The molecules and ions that make up liquids and solutions are also continually moving in nearly random directions. As a result, molecules and ions in a solution will collide with one another fairly frequently. As with gases, a temperature increase will produce an increase in the average particle speed.
Consider the following text:
While out camping, Susie and Bob both make their own campfires to cook food on and keep warm. Susie puts a pot of water on her fire to use for coffee, and Bob puts his own pot of water on top of his fire. Suddenly, an odd man comes up and asks if he can measure their water pots for his scientific research. Hesitantly, Susie and Bob both agree, but feel odd about the situation. The man tells them that Susie's water molecules are moving very fast and Bob's aren't moving much. The man then sprints away. Bob and Susie look at each other with confused expressions.

Are the molecules in Susie's water colliding more or less frequently than Bob's?