Solids Liquids Gases 1

Solid- a substance that has a definite volume and shape Liquid- definite volume but takes the shape of its container (flows). Gas- a substance that has no definite volume or definite shape (flows) . 2

Soilds Particles are in motion and vibrate in place. Expand only slightly when heated Particles held closely together, usually in a regular arrangement or pattern. A crystalline solid is a solid whose atoms, ions, or molecules are arranged in an orderly, geometric, three-dimensional structure.

Liquid Indefinite shape, flows, yet has a fixed volume. Particles have enough energy to slide past one another. LIQUID FLOW Tend to expand when heated

Gases Expand to fill the container they are in. Also take volume of container. Are compressible. Compressible due to all the space between the particles.

Change of State When you go from one state of matter to another. Melting- the change in state from solid to liquid Solid ice cube turning into water Boiling (Evaporate)- the change in state from liquid to gas Watching boiling water turn into steam and evaporate Change of State

Freezing- the change in state from liquid to solid Water freezing into ice Condense- the change in state from a gas to a liquid Water on the outside of your car window Sublimation- Changing solid to gas Change of State

Phase changes that REQUIRE energy Melting- solid to liquid Evaporation- Liquid to gas Sublimation- Solid to gas

Phase changes that RELEASE energy Condensation- gas to liquid Freezing- liquid to solid Deposition- gas to solid

PHASE CHANGE Graph of temperature and pressure that shows in which phase a substance exists under certain conditions. You can predict at what phase your substance will be

Phase Change for CO2 Phase diagrams are different for each substance because the boiling and freezing point is different. Phase diagram for CO2 show why it sublimes at normal conditions. Notice how it changes from a solid to a gas at 1atm. We are going to increase the pressure and make CO2 go through the solid, liquid, and gas phase.

Heating/ Cooling Curve of a Water

Is it Endothermic or Exothermic? Exothermic – gives off energy/heat Gas to liquid to solid Endothermic – absorbs energy/heat solid to liquid to gas

1. When ice melts a) a phase change occurs from a solid phase to liquid phase b) an endothermic process occurs which requires energy c) the water changes from a crystalline solid to a liquid d) all of the above

2. When water freezes a) a phase change occurs from a liquid phase to a solid phase b) an exothermic process occurs where energy is lost from ice to the surroundings c) the liquid water changes from a random structure to a crystalline solid d) all of the above

3. Which statement is not true 3. Which statement is not true. a) to change from a solid to a liquid requires energy b) depending upon the temperature, water can exist in solid, liquid or gas states c) solids and liquids have similar densities because particles of solids and liquids both touch d) in a solid the molecules have no motion, and no energy.

4. Which of the following correctly describes what happens when an inflated balloon is compressed? A. When the gas is compressed, the particles get smaller. B. When the gas is compressed, the particles move closer together. C. When the gas is compressed, the particles get larger. D. When the gas is compressed, the particles move father apart.

5. Which of the following correctly describe the particles in a solid compared to the particles in a liquid? A. Particles in a solid are farther apart than particles in a liquid B. Particles in a liquid are much farther apart, than particles in a solid. C. Particles in a solid do not move at all, and particles in a liquid slide past one another. D. Particles in a solid vibrate in place and particles in a liquid slide past one another.

Describe what is happening at each step? 1. 2. 3. 4. 5.