1. II. Heat Energy A. Temperature is a measure of how fast the molecules hitting the thermometer are. Units are Fahrenheit, Celsius and Kelvin. It is a direct measurement. B. Heat is a measure of the energy of an entire SYSTEM. Units are calories and joules. Heat is calculated and depends on mass, specific heat and temperature. Weather unit

2. C. Heat Capacity Page 1 ESRT: specific heats of common materials 1. Specific heat is the energy (joules) that you must add to increase the temperature of 1 gram of a substance 1 degree Celsius. 2. Water has a high specific heat. It takes more than 5 times as much energy to change the temperature of a gram of water as to change the temperature of a gram of granite. Weather unit

3. D. Comparing land and water Water tends to: Heat slowly (absorption) and cool slowly (reradiation). Water moderates the temperatures around it. Water absorbs a lot of heat because it:  is transparent,  has a high specific heat,  moves and  evaporates. Land tends to: Heat quickly and cool quickly. Dry areas have huge changes in temperatures. Land is opaque; only the top layers are directly heated. It has a low specific heat. Weather unit

4. E. Heat Transfer Energy is exchanged when a source of energy transfers that energy to a substance. Conduction: molecule to molecule through vibration (solids and surfaces) Convection: in fluids, due to density differences Radiation: electromagnetic energy travels in waves, through space or materials. http://www.spectrose.com/modes-of-heat-transfer-conduction-convection-radiation.html Weather unit

5. III. Energy and Phase Changes A. To change ice to water at 0 degrees C, 334 joules/gram must be added. To change liquid to ice, 334 joules/gram must be removed. How do you remove heat? it must be ‘lost’ or ‘given’ to the environment. uwsp.edu Weather unit

6. B. Phases of water: p. 1 ESRT properties of water Phase describes the motion of the molecules: Gases are independent and move apart Liquids flow, but stay together Solids are locked in place. Since movement takes energy, solids are the ‘coldest’ Weather unit

7. C. Water phase change diagram Phase change diagram of water can be viewed ‘forward’ (adding heat) or ‘backward’ (removing heat). Flat lines indicate phase changes. Sloped lines indicate temperature change. Condensation warms the air around it Evaporation cools the air around it. Kentchemistry.com Weather unit

8. D. Water is Weird: density Density of water: at 3.98 degrees C, water is its most DENSE!!! the density is 1.0 g/ml At 0 degrees C, the density of water is less and ice floats!!!!! Water vapor: the hotter it is, the lighter it is. so, hot air rises…. michitravel.com Weather unit

9. E. Hot air: expands (takes up more room) and is lighter (rises) and water evaporates (vapor is light) Cold air: condenses (molecules close together) and water vapor changes phase into water drops. http://science-mattersblog.blogspot.com/2010/08/air-pressure-balloon- in-flask.html Weather unit