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Bellwork: Monday 4/30/2012

Bellwork: Monday 4/30/2012. All forms of matter, whether a solid, liquid, or gas, are composed of atoms or molecules in ____________ motion. Because of this, all atoms have ________________ energy.

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Bellwork: Monday 4/30/2012

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  1. Bellwork: Monday 4/30/2012 • All forms of matter, whether a solid, liquid, or gas, are composed of atoms or molecules in ____________ motion. • Because of this, all atoms have ________________ energy. • When a substance is heated, the atoms move _____________. When a substance is cooled, the atoms move _____________. • The "average motion" of the atoms that we sense is what we call ________________ Word Bank: temperature, slower, constant, faster, thermal (heat) constant thermal (heat) faster slower temperature

  2. FRIDAY!!!Tasty Phase Change – The Ice Cream Lab! I will buy the supplies to make the ice cream…but you all must bring in any toppings you would like! Examples: chocolate syrup, chocolate chips, gummy bears, crumbled cookies, sprinkles, cookie dough, cherries, cool whip, anything else you like on your ice cream!!!

  3. Packet 13- Page 1 What is Energy?? • Energy- the ability to do work • Energy can be transferred from one object to another by doing work • When work is done on an object, it results in a change in the object's motion (more specifically, a change in the object's kinetic energy)

  4. Temperature vs. Heat Page 1- Temperature and heat ARE NOT technically the same thing. • Temperature- a MEASURE of the average kinetic energy of the molecules of a substance • Heat – the TRANSFER of thermal energy from a warmer object to a cooler object • Note: This is a different definition than the “common” one people use daily

  5. Facts about Water. • Hydrology- study of water Facts: • Nearly 70% of the earth's surface is covered with water • Most of the earth's water is either salt water (97%) or in the form of ice and snow (2%) • Only 1% of the earth's water is available for us to drink What do you already know about the Water Cycle?

  6. Continuous process: same water used over and over again The water on the earth today has been there for millions of years Water moves: earth  air  earth Water changes: solid(snow and sleet)  liquid (rain, river water, groundwater)  gas (water vapor) Water Cycle

  7. 7.6- TSW DESCRIBE HOW SOLAR ENERGY DRIVES THE WATER CYCLE • How does solar energy drive the water cycle? • Solar energy heats water on the surface, causing it to evaporate • SOLAR ENERGY DRIVES THE WATER CYCLE

  8. Solar Energy and the Water Cycle • Evaporation- liquid absorbs enough energy to change into a gas • Transpiration- water evaporates through a plant's leaves • Condensation- gas (water vapor)  liquid • Precipitation- forms of water that fall back to the Earth's surface • Depends on temperature: rain, sleet, hail, or snow

  9. Heat Transfer~Transfer of thermal energy~ Heat is transferred through: 1. Conduction 2. Convection 3. Radiation

  10. Conduction- transfer of heat through a solid material; transfer of energy from one molecule to another; occurs when molecules hit against each other • similar to a game of pool where one moving ball strikes another, causing the second to move

  11. Conductor- a material which easily allows the flow of electricity or heat through it • Most metals are good conductors • Metallic bonds = hippie bonds = free flowing e’ • Ex. iron, copper • Insulator- a material which does not easily allow the flow of electricity or heat through it • Ex. glass, plastic, rubber, air, wood • used to protect us from the dangerous effects of electricity flowing through conductors

  12. Where is the safest place to be outside in a lighting storm?? • Your car! • The electrical current travels along the outside of a conductor (the metal body of the car). • Eventually it will dissipate to the ground through paths that include the tires (insulator) and water. • What should you do if it happens to you? • Pull off to side of the road in a safe manner, turn on emergency blinkers, turn off engine. • Put hands in your lap! Do not touch metal objects like door/window handles, radio dials, steering wheel, & inside-outside metal objects. • Wait out the storm. DO NOT step out of the vehicle in an attempt to find another shelter. • Lightning voltages will attempt to equalize themselves, and they may go through a person in order to do so.

  13. Convection- transfer of heat by the movement of a fluid (liquid or gas); Convection current- circular motion caused by convection; hot rises, cold falls

  14. Radiation- transfer of energy by electromagnetic waves

  15. All three forms of heat transfer:

  16. In-Class Individual Work (10 mins): Chapter 14- (pg 439) Thermal Energy & Heat Nature of Heat Worksheet (Pkt 13, Pg 2) • Use the Physical Science textbook to complete • You will not be able to start the lab tomorrow until you finish these pages!

  17. Bellwork: Tuesday 5/1/2012 Roughly sketch the picture below. Label the three types of heat transfer on the diagram. Then, define the three types of heat transfer in your own words. 1. convection Movement of actual fluid (liquid or gas) Hot rises, cool sinks 3. radiation Transferred by electromagnetic waves (infrared, visible) 2. conduction Transfer from one particle of matter to another particle

  18. In-Class Individual Work (10 mins): Chapter 14- (pg 439) Thermal Energy & Heat Nature of Heat Worksheet (Pkt 13, Pg 2) • Use the Physical Science textbook to complete • You will not be able to start the lab today until you finish these pages! Show me they are done before you start!

  19. FRIDAY!!!Tasty Phase Change – The Ice Cream Lab! I will buy the supplies to make the ice cream…but you all must bring in any toppings you would like! Examples: chocolate syrup, chocolate chips, gummy bears, crumbled cookies, sprinkles, cookie dough, cherries, cool whip, anything else you like on your ice cream!!!

  20. Conduction, Convection, Radiation Lab- pages 3 Finish Lab Stations Complete Conclusion Questions; Work on Homework- Heat on the Move Page 4

  21. Think about it…ACC • Have you ever noticed that metals tend to feel cold? Why? • Believe it or not, they are not colder! They only feel colder because they conduct heat away from your hand. You perceive the heat that is leaving your hand as cold.

  22. Bellwork: Wednesday 5/2/2012 • Conductor or Insulator? Write statement, then write “c” or “i” • Plastic handle of a frying pan • Copper tea kettle • Cloth jacket • Wooden walls of a house • Oven mitts • Copper wires used to heat an electric blanket • Aluminum surface of a cooking pot • Wool hat • Metal radiator • Feathers of a bird

  23. FRIDAY!!!Tasty Phase Change – The Ice Cream Lab! I will buy the supplies to make the ice cream…but you all must bring in any toppings you would like! Examples: chocolate syrup, chocolate chips, gummy bears, crumbled cookies, sprinkles, cookie dough, cherries, cool whip, anything else you like on your ice cream!!!

  24. Ice Hotel • Understanding the states of matter is important to engineers and other builders. However, those who build out of ice must have a special knowledge of the solid state of water. • Building Igloos or Snow-and-Ice Houses- After the blocks are secured, a lamp is lit inside. Heat from the lamp __________ the snow on the inside walls. The water would then _________ when cold air was let in from the outside. melts freeze • The melted and rehardened snow functions as a cement. Gradually, the heat from people living and working inside changes the snow dome into a solid dome of ice!

  25. $240 per person/night lowest quality room - $1,111 per person for deluxe suite; $1400 flight • Not able to take your personal belongings into ICE HOTEL as they will freeze! • Secure areas and bathroom areas and sauna in warm accommodation are located just next to ICE HOTEL • Art exhibit during the daytime

  26. In-Class Individual Work: • Chapter 2 (pg 64)- Solids, Liquids, & Gases • Changes in State (Pages 4-5) • Use the Physical Science textbook to complete • Phase Change Diagram (Page 6) • Phase Change Graph (Page 6) • You will not be able to start the lab tomorrow until you finish these pages!

  27. Phase Change Diagram- Page 6 • You will refer to this for tomorrow’s lab and future assignments on phase changes.

  28. Bellwork: Thursday 5/3/2013Complete this phase change diagram. Write the names of the: ~ phases/states of matter on the dashed lines ~ phase transitions on the arrows Gas Evaporation Freezing Liquid Solid Condensation Melting

  29. FRIDAY!!! TOMORROW!!!Tasty Phase Change – The Ice Cream Lab! I will buy the supplies to make the ice cream…but you all must bring in any toppings you would like! Examples: chocolate syrup, chocolate chips, gummy bears, crumbled cookies, sprinkles, cookie dough, cherries, cool whip, anything else you like on your ice cream!!!

  30. Phase Changes Lab- Pages 7-8 • Work in table groups (2-4 people) • Who is the timer and calling when 30 seconds has passed? (don’t stop the stopwatch, let it run continuously) • Who is reading the thermometer and calling out the temperature? (Celsius on the right side of the thermometer) • Take measurements for ~15 minutes, every 30 sec • Don’t leave the thermometer unattended in the beaker • Who is recording the data every 30 seconds on the data table? • HOT plates are VERY HOT DO NOT TOUCH • Don’t touch the beaker—I will use hot mitts!! • Do not let the cord touch the hot plate. • Homework: • Finish Lab Conclusion Questions (9-10)

  31. Bellwork: Friday 5/4/2012 Water Freezing… • Physical/Chemical Change? • Physical- phase change; no new substance • What kind of phase change ____  _____? • Liquid Solid • Energy absorbed/released? • Energy is released • Molecular motion? • Less energy = less movement; Always in constant motion • Freezing point of water? • 32 °F or 0 °C

  32. Ice Cream Lab • Roles & Responsibilities • Salt and Ice (in big bag) • Milk, vanilla, sugar (small bag) • Cups and spoons for group • Towel for wiping spills; protective outside bag • Groups of 3 or 4 • Gallon (Big bag): salt and ice • Quart (Small bag): milk, sugar, vanilla • ~10-15mins of mixing until it’s done • Ice cream toppings • Make sure you are recording the temperature (page 11) and thinking about the conclusion questions (page 12)!! EVERYTHING MUST STAY NEAT & CLEAN, PLEASE!!

  33. What happens to the molecular arrangement of H2O when water freezes? • Freezing: liquid  solid • Its molecules go from a disorganized state to an organized state.

  34. Water vs. Salt Water Densely packed blue spheres water molecules solidified into ice (crystalline structure) Loosely packed blue spheres water molecules as a liquid free water molecules randomly moving around in all directions Salt (black spheres) dissolved into water

  35. What happens to salt when it is dissolved in water? • H2O = pure water • NaCl = salt • Na+ and Cl- = Ionic compound • H2O separates the Na+ and Cl- ions present • H2O molecules arrange themselves around the Na+ and Cl- ions , shielding the H2O molecules from interacting with each other • Result: It’s harder to make a structure of ice

  36. How this effects the freezing point of water • Water molecules have a harder time coming together • Water molecules have to be slowed down even more in the presence of salt in order to form a solid.  • So you have to go to a lower temperature in order to freeze water when it has salt dissolved. 

  37. Adding a solute to a solution • Adding a solute to water allows for less contact between H2O molecules • Freezing Point • lowers the freezing point • Normal freezing point: 32 °F or 0 °C • Salty water will still freeze, but the temperature has to be colder than it would for normal water. • How much colder? • The more salt you add, the colder it must get before the water freezes. • Boiling Point • Raises the boiling point

  38. Some Salty News • Very salty lake waters at Death Valley, California (approximately 300,000 parts per million “salt”) may freeze and melt at temperatures as low as -20 to -30°C!

  39. Bellwork: Friday 4/24/2010 • In order for matter to change phase ___________ must be either gained or lost. • If you have ever lived in a place where it snows, then you know salt is sprinkled on sidewalks and streets. Why? • to melt the snow or ice • Oceans don’t freeze except in extreme polar regions. Why? • Salt water needs to be colder! Heat / energy

  40. Transferring Thermal Energy:Conduction, convection or radiation?? (more than one?) Someone places a hand on a metal table and the hand feels cold. Hot air currents inside a balloon causes the balloon to rise. Energy from the sun travels to the surface of Earth. Storm clouds form when warm air moves into the atmosphere. Heat from a stove warms a pot of soup. A person turns on a lamp and feels its warmth on his hand. The heat from a space heater rises to the top of a room and is replaced by cooler air. A metal spoon stirring a cup of hot cocoa becomes warm. Water in a swimming pool is warmed by the sun. A person swimming in the ocean begins to feel cooler. Conduction Convection Radiation Convection Conduction, Convection Radiation Convection Conduction Radiation Conduction Identify the correct type of heat transfer for each, and what heat is transferring from—to. Remember, heat transfers from hot to cold.

  41. Why did we need salt to make our ice cream? • Salt “gets in the way” of the interactions between H and O, making it harder for the H and O to bond as ice. • Salt lowers the freezing point of water • So you have to go to a lower temperature in order to freeze water when it has salt dissolved.  • Overall Idea: Water molecules have to be slowed down even more in the presence of salt in order to form a solid. Can salt water ever freeze? • Yes, salty water will still freeze, but the temperature has to be colder than it would need to be for pure water. • How much colder? • More salt you add, the colder it must get before the water freezes • Very salty lake waters at Death Valley, California (approximately 300,000 parts per million “salt”) may freeze and melt at temperatures as low as -20 to -30°C! • In general: Adding a solute to water lowers the freezing point of that solution because its allows for less contact between H2O molecules • What else would adding salt affect? • Also raises the boiling point

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