Chapter 2: Solids, Liquids, and Gases

Lesson 1: States of Matter

  1. Solids
  2. Definite shape and definite volume
  3. Particles packed tight in fixed position
  4. Particles cannot move
  5. Particles only vibrate in place—This is why solids are “solid”
  6. Types of solids
  7. Crystalline Solids
  8. Particles form regular repeating patterns which create crystals.
  9. Examples: salt, sugar, snow, diamonds
  10. Have specific melting points
  11. Amorphous Solids
  12. Particles are not arranged in a repeating pattern
  13. Does not have a specific melting point
  14. May soften with heat
  15. May change into a different another substance
  16. Examples: glass, plastics, rubber—each softens with heat and the shape of each substance can change with heat
  17. Liquids
  18. Has a definite volume but no shape without a container
  19. If the same volume of liquid is poured into two differently shaped containers, the shape appears to change but the volume will not change.
  20. Particles are packed close together but move around each other freely
  21. Because particles are free to move liquids have no set shape.
  22. Liquids are fluids—“substances that flow”
  1. Properties of Liquids
  2. Surface tension-
  3. Water molecules are very attracted to each other
  4. Surface of water acts like a “skin” or barrier
  5. Viscosity
  6. A liquid’s resistance to flowing
  7. Viscosity depends on the size and shape of the particles and the attraction that may exist between particles.
  8. High viscosity = flow slowly
  9. Low viscosity = flow easily
  1. Gas
  2. Definition- matter that has no definite shape or volume.
  3. Describing Gas
  4. Volume- The amount of space matter takes up.
  5. Measured in cubic centimeters -cm3 cubic meters -m3 milliliters-mL and liters-L
  6. Particles will spread out to fill an entire container—like a balloon or SCUBA tank.
  7. Pressure-the pressure of a gas is the force of its outward push divided by the area of the walls of the container. Pressure= Force

Area

  1. Temperature- a measure of the average energy of random motion of the particles of matter.
  1. The faster the particles are moving, the greater their energy and the higher the temperature.
  1. The slower the particles are moving, the lesser their energy and the lower the temperature.

Lesson 2 Changes of State

  1. Melting –the change in state from solid to a liquid
  2. The particles of the solid vibrate so quickly they break free from their fixed positions.
  3. Thermal energy increases as temperature increases.
  4. Occurs at a specific temperature in crystalline solids called the melting point.
  5. Physical property of a substance.
  6. Unknown substances can be identified by their melting points.
  1. Freezing- The change in state from a liquid to a solid
  2. The particles are moving so slowly that they begin to take on fixed positions.
  3. Thermal energy decreases as temperature decreases.
  4. Vaporization – The change in state from a liquid to a gas
  5. Particles within a liquid gain enough energy to move independently.
  6. Evaporation-takes place at the surface of a liquid (shrinking puddle)
  7. Boiling- vaporization takes place at the below the surface and at the surface of a liquid (boiling water on the stove)
  8. Boiling Point- The temperature at which liquids boil
  9. Unknown liquids could be identified by their boiling points.
  10. Condensation- Change in state from gas to a liquid
  11. Occurs when the particles of a gas lose enough thermal energy to form a liquid (clouds)
  12. Sublimation- change in state from solid to a gas
  13. Particles of a solid do not pass through the liquid state as they form as gas.
  14. Particles gain enough energy to move directly from a fixed position to moving independently.

Lesson 3- Gas Behavior

  1. Temperature and Pressure are related
  2. When the temperature of a gas at a constant volume (closed container) is increased, the pressure increases.
  3. When the temperature of a gas at a constant volume (closed container) is decreased, the pressure decreases.
  1. Volume and Temperature are related
  2. Charles Law
  3. When the temperature of a gas at a constant pressure is increased, it’s volume increases.
  4. Balloon on a hot day—The helium inside the balloon heats up and the balloon expands because the volume of the helium expands.
  1. When the temperature of a gas at a constant pressure is decreased, its volume decreases.
  2. Car tires in the winter- as the temperature outside decreases, the temperature of the air inside the tires decreases. This causes the molecules within the air to move closer together—decreasing the volume. This makes the tires flatten.
  3. They haven’t “lost air”
  1. The relationship between the volume and temperature of a gas is directly proportional

Charles’ Law



  1. Pressure and Volume are related
  1. Boyle’s Law
  2. When pressure of a gas at a constant temperature is increased, the volume of the gas decreases.
  1. When the pressure of a gas at a constant temperature is decreased the volume of the gas increases.
  2. The relationship between the pressure and volume of a gas on a graph is inversely proportional

Boyles’ Law