Summary and Evaluation of Types of Energy The kinetic theory of matter assumes that matter is made up of tiny particles such as atoms, molecules and ions that are constantly moving and therefore possess kinetic energy. The kinetic theory of gases is based on a set of assumptions that help explain the behavior of gases. There are several key assumptions in the kinetic theory; and they have been explained in this chapter. Every substance in the world is either a solid, a liquid or a gas. Some substance can exist in all the three states. Solids have definite shape and therefore definite volume. They are not easily squeezed because the atoms or molecules in solids are packed closely together and arranged in a regular way. Liquids have no definite shape. They take the shape of the container they are put in. The molecules in liquids move about but they are still quite close together. The forces between the molecules in a gas are negligible. As such, the gas molecules are not attracted to each other. There are large spaces between the molecules, so gases can be compressed and expanded. The average kinetic energy of molecules in: Solids is insufficient to overcome the forces that attract the molecules to each other; Liquids is greater than that of solids, so the molecules are less rigidly held; Gases is strong enough to overcome the forces binding the molecules together, so they (the molecules) are independent of one another and move about randomly. Diffusion is the natural tendency of molecules to flow from higher concentrations to lower concentrations. Brownian motion is a random movement of microscopic particles suspended in liquids or gases resulting from the impact of molecules of the surrounding medium. It is also known as Brownian movement. The kinetic theory of matter can be used to explain many observable scientific facts. Among which are: the pressure of gases, evaporation of liquids, boiling of liquids and rates (speeds) of chemical reaction. Boyle’s law is a gas law that states that a gas’s pressure and volume are inversely proportional. Gay-Lussac’s law, Amontons’ law or the pressure law was founded by Joseph Louis Gay-Lussac in 1808. It states that, for a given mass and constant volume of an ideal gas, the pressure exerted on the sides of its container is directly proportional to its absolute temperature. Evaporation is the escaping of molecules of a liquid from its surface. It takes place at all temperatures. Boiling is the vaporization of liquid molecules throughout the entire liquid. The temperature at which a liquid changes into vapour is called its boiling point.  This chapter also treated the difference between boiling and evaporation. The following are the factors that can affect evaporation: Temperature, Amount of liquid available, Pressure, The nature of the liquid, Surface area of the liquid exposed, Humidity, Impurities, Climatic factors and Intermolecular forces of attraction. EVALUATION State five factors that can affect evaporation. Describe the kinetic theory of matter State five assumptions of the kinetic theory Briefly describe the three states of matter What is diffusion? What’s another name for Brownian motion? State the following: Boyle’s law Gay-Lussac’s law Describe the following: Boiling Evaporation In three ways, distinguish between boiling and evaporation