Chapter 2 – Solids, Liquids, and Gases 2.1 States Of Matter

I. Essential Question: How do you describe a solid? How do you describe a liquid? How do you describe a gas?

II. Key Vocabulary Solid: definite shape and definite volume Crystalline solid: solids that are made of crystals (regular, repeating patterns) Amorphous solid: solids that do have particles arranged in a regular pattern.

II. Key Vocabulary Liquid: definite volume but no definite shape Fluid: a substance that flows Surface tension: an inward force (pull) among the molecules in the liquid that brings the molecules on the surface closer together. Viscosity: a liquid’s resistance to flowing; depends on the size/shape of its particles and their interaction.

II. Key Vocabulary Gas: neither a definite shape nor a definite volume Pressure: the force of a gas’s outward push divided by the area of the walls of the container; measured in pascals (Pa) Pressure = Force / Area

III. Key Concepts – Solids Particles in a solid are packed close together. The particles are limited in movement – vibrate in place. Crystalline solids melt at a distinct temp; amorphous solids do not melt – they get softer and can bend.

III. Key Concepts – Liquids Particles in a liquid are still packed somewhat close together. The particles can move around one another freely. Liquids high in viscosity flow slowly; liquids low in viscosity flow quickly.

III. Key Concepts - Gases When gas particles move, they spread further and further apart; they can move freely to fill all open space. The volume of a gas is the same as the volume of its container. Concentration refers to the number of gas particles in a given unit of volume. The higher the temp, the faster the gas particles will move .

Chapter 2 – Solids, Liquids, and Gases 2.2 Changes of State

I. Essential Question: What happens to the particles of a solid as it melts? What happens to the particles of a liquid as it vaporizes? What happens to the particles of a solid as it sublimes?

II. Key Vocabulary Melting: changing from a solid to a liquid Melting point: a specific temperature that causes melting Freezing: changing from a liquid to a solid Vaporization: change of state from a liquid to a gas

II. Key Vocabulary Evaporation: vaporization that takes place only on the surface of a liquid Boiling: vaporization that takes place both below and at the surface of a liquid Boiling point: the temperature at which a liquid boils

II. Key Vocabulary Condensation: change in state from a gas to a liquid Sublimation: occurs when the surface particles of a solid gain enough energy that they form a gas

III. Key Concepts From solid to liquid or liquid to gas – increase in thermal energy; from gas to liquid or liquid to solid – decrease in thermal energy. Different substances have different melting points, so it can be used to identify unknown substances. During melting, particles gain energy and break free; during freezing, they slow down and become fixed.

III. Key Concepts Different substances have different boiling points, so it can be used to identify unknown substances. During boiling, particles gain energy and break free; during condensation, they slow down and become fixed.

Chapter 2 – Solids, Liquids, and Gases 2.3 Gas Behavior

I. Essential Question: How are pressure and temperature of a gas related? How are volume and temperature of a gas related? How are pressure and volume of a gas related?

II. Key Vocabulary Charles’s Law: when the temp of a gas at constant pressure is increased, volume increases; the opposite is also true. Directly proportional: when one item increases, so does the other one.

II. Key Vocabulary Boyle’s Law: when the pressure of a gas at constant temp is increases, the volume decreases; the opposite is also true. Inversely proportional: when one item increase, the other one decreases.

III. Key Concepts When the temp of a gas at a constant volume is increase, the pressure increases. If you heat particles, they begin to move more quickly; this means they will hit the container more frequently = increased pressure.