RRB pages Heat Energy and Changes of State and Earth’s Energy Supply

PHASE CHANGE NAMEPROCESS MATERIAL GAIN OR RELEASE ENERGY? EXAMPLE Melting Changing of a solid to a liquid GainedLeft out ice cream Solidification (Freezing) Changing of a liquid to a solid ReleasedMaking ice cubes Crystallization Changing to a solid with an ordered pattern ReleasedRock candy Evaporation (Vaporization) Changing of a liquid to a gas or vapor GainedVaporizer used when sick Condensation Changing of a gas or vapor to liquid Released Foggy mirror after shower SublimationChanging of a gas directly to a solid or from a solid directly to a gas Gain if going to gas, released if going to solid Dry ice Types of Change of State *Note: Properties of water on ESRT page 1

Stored Heat and Changes of State A material’s temperature rises as heat is added to it unless the material is in the process of changing state, then the temperature will remain the same as it is heated A cheesy 80s video to help explain the concept

Stored Heat and Changes of State of Water Freezing point of water= 0 degrees C Boiling point of water= 100 degrees C When water reaches 0 degrees C or 100 degrees C, it will remain at that temperature for a period of time during the change in state This is due to the fact that the heat that is being added is being changed to stored heat (potential energy)

Earth’s Energy Supply MEMORY JOGGER: The energy for Earth’s processes comes from mostly the sun but also Earth’s interior

Solar Energy Earth receives electromagnetic energy of varying wavelengths from the sun Solar energy is produced by nuclear fusion (see notes on the sun in the astronomy unit)

Earth's Own Energy Heat energy from Earth’s interior is converted into mechanical energy for mountain building, volcanic eruptions, plate movements and other internal movements Some of this heat is from when Earth formed Some is the result of materials being pulled by gravity towards Earth’s center Most of the energy in the interior comes from nuclear decay of radioactive material within Earth Nuclear decay (aka nuclear fission): the process by which unstable or radioactive atomic nuclei of elements split to form lighter elements, resulting in the release of high amounts of energy Nuclear decay is used to produce a portion of the nation’s electric supply (ie. Indian Point)

EXIT PASS In groups of 3-4… Write ONLY the process. Be sure all names are on your paper Determine the change in state occurring in each of these examples: Example: Water turning into ice: liquid->solid (solidification) a. Dew on a car window b. A pot of water on a counter going from a level of 2 liters to a level of 1 liter in a period of 3 days c. A smoke machine at a dance d. Breathing on a mirror and fogging it up