CHEM 103 Module 6 notes and problem set.>THE LIQUID STATE OF MATTER

THE LIQUID STATE OF MATTER Liquid water is common, but because liquids can exist only within a relatively narrow range of temperatures and pressures, the liquid state is the least common state of matter in the universe. For example, of the 92 naturally occurring elements, 79 are solids, 11 are gases, and only two (bromine and mercury) are liquids. Earlier we used the kinetic molecular theory to explain the properties of gases. This same theory is used to explain the properties of liquids. Liquids have less kinetic energy than gases, so the intermolecular attractive forces are strong enough to hold the liquid particles close together but not strong enough to keep neighboring particles in a fixed position, meaning the particles are free to move past or slide over one another. SOLID LIQUID GAS A liquid has a definite volume but not a definite shape because the intermolecular attractive forces are strong enough to hold the particles close together. Like a gas, a liquid takes the shape of its container (but just the lower part of the container, whereas a gas fills the entire container). Liquids and gases are both fluids because the particles that make up the liquid are moving (vibrating a