13.2. Liquids and Solids http://www.ck12.org
13.2 Liquids and Solids
Lesson Objectives
- Compare and contrast the properties of liquids and solids both at the macroscopic level and at the molecular
level. - Explain the concept of viscosity and give examples of substances that are more viscous and less viscous than
water. - Define surface tension and vapor pressure.
- List the four types of solid crystals based on how the particles are bonded together, and give examples of each.
Lesson Vocabulary
- viscosity: Measures a fluid’s resistance to flow.
- surface tension: The amount of energy required to increase the surface area of a liquid.
- adhesion: A liquid that displays more attraction between the liquid and the glass than attraction between the
liquid particles. - cohesion: A liquid that that displays more attraction between the liquid particles than attraction between the
liquid and the glass - vapor pressure: A measure of the pressure exerted by a gas above a liquid in a sealed container.
- crystalline solids: Solid substances in which the arrangement of particles is highly ordered.
Check Your Understanding
- Would particles in the solid, liquid, or gas phase have the greatest average kinetic energy?
Introduction
You encounter solids and liquids in many forms in your everyday life. Solids, unlike liquids, hold a definite shape.
Both solids and liquids hold a definite volume. However, on a molecular level, these two states of matter are quite
different. In this lesson we will introduce some of the properties of liquids and solids that affect your interactions
with the substances all around you.
Liquids
Liquids have a definite volume, but no definite shape. A gallon of milk will keep the same volume whether it is
stored in a one-gallon milk jug or a ten-gallon barrel. The volume is the same, but the fluid will either fill the jug or