2 Objectives> Explain physical change, and give examples of physical changes.> Explain chemical change, and give examples of chemical changes.> Compare and contrast physical and chemical changes.> Describe how to detect whether a chemical change has occurred.
3 Phases of Matter There are 4 phases of Matter Solid, Liquid, Gas, PlasmaMolecules are always moving. They can vibrate and they can expand.
7 Molecular movement Solids – molecules constantly vibrating Liquids- molecules are spreadingGases – Molecules are expanding
8 Phases of MatterMatter can change from form to form depending on the amount of energy (heat) is available.Solid to liquid to gas.Ice in a pan melts then begins to boil and turn to steam.
9 Phase changes & Temperature ___________/_________________Phase changes occur at 1 temperature.
10 Physical ChangesPhysical changes occur without creating something new. They effect the physical properties of a substance. Such as melting, mixing, or dissolving. If you can change it back it is a physical change.
11 Chemical changesChemical changes occur when the composition is changed and something different is created.You can tell because of odor, bubbles, color changes, sound, heat or light.Chemical Change Clip
12 Chemical changesChemical changes can not be reversed to go back to original state.Chemical changes can break down compound such as water to create hydrogen and oxygen.
14 Phases of matter Solids- definite shape and volume Crystalline- orderly arrangement of atoms- diamondAmorphous-opposite- gum
15 Phases Cont’d Liquid- definite volume no definite shape. Surface tension-force acting on particles at the surface causing droplets to form.
16 Phases Cont’d Gas- no definite shape and no definite volume. Particles expand and spread out.
17 Change in phase/stateCondensation- energy released when gas changes to a liquidTemperature and state do not change together
18 Energy Released to Solidify Energy is absorbed when water vaporizes; the same amount of energy is released when the water vapor condenses.100908070605040302010Energy must be added to separate the particles as ice melts; the same amount of energy is released when water freezes.EnergyabsorbedTo vaporizeEnergyReleased to condenseEnergy Released to SolidifyEnergy absorbedto melt– Relative energy Temperature (˚C)
19 Change in phase/stateEvaporization- energy required to change liquid to gasSublimation- energy required to change solid to a gasStates of Matter Clip