2Energy Basics The Law of Conservation of Energy Energy canNOT be created or destroyedIt may be Transformed to another formIt may be transferred from one object to anotherTOTAL ENERGY ALWAYS STAYS THE SAME
3Three main forms of energy Potential EnergyKinetic EnergyHeat EnergyLight Energy
4Potential EnergyPotential Energy: when an object stores energy. Examples:Chemical Potential Energy : sugar is a chemical that stores energyGravitation Potential Energy : when an object is elevated against Earth’s gravityOther Examples: A stretched Rubber Band
6Heat EnergyHeat Energy: Energy in the form of moving atoms/ kinetic energy of atoms.
7Light Energy:Light Energy: Energy in the form of light waves/ photons.
8Transformation of Energy Energy canNOT be created or destroyedIt may be Tranformed to another formExamples:Light energy is transformed to chemical energy (sugar) by photosynthesis in plantsChemical Energy (sugar) is transformed to heat energy by respiration in living organismsGravitational Potential energy is transformed to kinetic energy when a ball is dropped.
9Transfer of energy Energy canNOT be created or destroyed It may be transferred from one object to anotherENERGY STAYS IN THE SAME FORM, BUT MOVES TO A DIFFERENT OBJECT.Examples:The Kinetic Energy of a the queue/ white ball is transferred to the 8 ball during a pool game.
10Practice: what kind of energy does this climber have?
11Rube Goldberg Video Energy Transfer or Transformation? Explain: Energy forms involvedWhere does the transfer/ transformation take place?
12Does a windmill represent energy transfer or transformation? Explain:Energy forms involved?Where does the transfer/ transformation take place?
13Deep Water Solo: http://www.youtube.com/watch?v=c5ZLctA-pcY Energy Transfer or Transformation?Explain:Energy forms involved?Where does the transfer/ transformation take place?
14Do solar panels represent energy transfer or transformation? Explain:Energy forms involved?Where does the transfer/ transformation take place?
15Is this an energy transfer or transformation? Explain:Energy forms involved?Where does the transfer/ transformation take place?
16Today’s Activity Safety Considerations: Goggles and Lab coats must be warn at all timesIf you spill anything on your hands or other body parts, DON’t Panic but wash in the sink immediately.Don’t get any chemicals in your eyes but if you do let me know immediately and we will flush it with water.NO HORSE PLAY …STAY SERIOUS….
17Today’s Activity Safety Considerations: Wash your hands after you leave the lab todayDON’T through matches in the garbage. There are tin cans to dispose of them.DON’T light anything on fire that you are not suppose to………Follow directions carefullyBe mindful of your movement in the lab and the movement of others.
18Station 1:Teacher Demo Sodium and Water Na + H20 ---> NaOH + H2 What do you observer?Is this a energy transfer or Transformation?Explain1000 ml Pyrex (flame/ hear resistant) Beaker of distilled water with phenaltheline indicatorTiny pieces of sodium metalLatex glovesA knife to cut sodium into small pieces.Safety goggles
19Teacher Demo Station 2Solid barium hydroxide reacted with solid ammonium thiocyanate produces barium thiocyanate, ammonia gas, and liquid water.Solid barium hydroxide reacted with solid ammonium thiocyanate produces barium thiocyanate, ammonia gas, and liquid water. This reaction gets down to -20°C or -30°C, which is more than cold enough to freeze water. It's also cold enough to give you frostbite, so be careful! The reaction proceeds according to the following equation: Ba(OH)2.8H2O (s) + 2 NH4SCN (s) --> Ba(SCN)2 (s) + 10 H2O (l) + 2 NH3 (g) Here's what you need to use this reaction as a demonstration: 32g barium hydroxide octahydrate17g ammonium thiocyanate (or could use ammonium nitrate or ammonium chloride)125-ml flaskstirring rodPour the barium hydroxide and ammonium thiocyanate into the flask.Stir the mixture.The odor of ammonia should become evident within about 30 seconds. If you hold a piece of dampened litmus paper over the reaction you can watch a color change showing that the gas produced by the reaction is basic.Liquid will be produced, which will freeze into a slush as the reaction proceeds.If you set the flask on a damp block of wood or piece of cardboard while performing the reaction you can freeze the bottom of the flask to the wood or paper. You can touch the outside of the flask, but don't hold it in your hand while performing the reaction.After the demonstration is completed, the contents of the flask can be washed down the drain with water. Do not drink the contents of the flask. Avoid skin contact. If you get any solution on your skin, rinse it off with water.
20Station 3: Rub your hands together for 30 seconds. Write down what you observe.
21Station 4: Burn Magnesium Magnesium & OxygenCAUTION: Do not look directly at burning magnesium.Position a watch glass near the gas burner.Using crucible tongs, grasp one end of the 5-cm strip of magnesium ribbon and hold it in the burner flame until the magnesium ignites.Quickly position the burning magnesium so that the combustion products fall on the watch glass.Materials:Watch glassGas burnerCrucible tongs5 cm Magnesium stripsmatches
22Station 5: Drop a marble into clay Drop a marble into clay from two different heights30 cm90cmMeasure and record the diameter of the crater formed in mmWrite down your observations and give a reason for your resultsMaterials:Steel ball of known massBox lined with soft modeling clayMeter stickRuler
23Station 6Add 30 drops (2 mL) of Hydrogen Peroxide to a medium-sized test tube. Clamp the test tube to a ring stand.Add a little bit of soap to catch gas. Add 10 drops (1 mL) of potassium iodide to a different test tube. Quickly pour the KI to the H2O2.Record your Observations: What do you see?Soapy waterKI Potassium Iodide300mL 10 %Hydrogen peroxide2 medium sized Test TubeRing standTest tube clamp
24Station 7 Place 20 drops (2 mL) of HCl into one of your test tubes. Add 2-3 pieces of MagnesiumFeel the test tubeRecord your Observations: What do you see, hear & feel?500mL 3 % HCl3cm strips of magnesiumTest tubeSmall test tube rackTest tube tongsgoggles
25Station 8Procedure:Attach a sticky note to the widest side of an eraser. Make sure the sticky note covers the entire side of the eraserPlace the eraser from step 1 note side down, next to a second eraser so that one end of each eraser extends 2 cm over the end of the table.Use a ruler to strike both erasers evenly and firmly at the same time.Measure and record the distance each eraser slides from the end of the table.Record the sliding distance in OBSERVATIONS:Complete your energy activity table for station 82 ErasersSticky noteMeter stickRuler
26Station 9 Place 20 drops of Acetic Acid into one of your test tubes Using a thermometer record the temperature of the acetic acid solution.Add 1 tiny scoop of Sodium Bicarbonate Feel the test tubeRecord the new temperature of the mixture.Complete your energy activity table for station 8500 mL white vinegar (acetic acid)Box of sodium BicarbonateTest tubeTest tube brushTest tube rackthermometer
27Station 10Measure some water (somewhere between mL) in a graduated cylinder and add it to a beaker.Before heating, record the temperature of the water (do not let the thermometer touch the glass).Holding the chip with tongs, use a match to start the chip on fire.Heat the water with the burning chip.After the chip is completely burned, record the final temperature of the waterComplete your energy activity table for station 9
28Station 10 Set-up Materials Ring stand Iron ring Thermometer clamp BeakerWire meshTongs200 Potato chips