Energy Basics

Energy Basics The Law of Conservation of Energy Energy canNOT be created or destroyed It may be Transformed to another form It may be transferred from one object to another TOTAL ENERGY ALWAYS STAYS THE SAME

Three main forms of energy Potential Energy Kinetic Energy Heat Energy Light Energy

Potential Energy Potential Energy: when an object stores energy. Examples: Chemical Potential Energy : sugar is a chemical that stores energy Gravitation Potential Energy : when an object is elevated against Earth’s gravity Other Examples: A stretched Rubber Band

Kinetic Energy Kinetic Energy : Energy of Motion

Heat Energy Heat Energy: Energy in the form of moving atoms/ kinetic energy of atoms.

Light Energy: Light Energy: Energy in the form of light waves/ photons.

Transformation of Energy Energy canNOT be created or destroyed It may be Tranformed to another form Examples: Light energy is transformed to chemical energy (sugar) by photosynthesis in plants Chemical Energy (sugar) is transformed to heat energy by respiration in living organisms Gravitational Potential energy is transformed to kinetic energy when a ball is dropped.

Transfer of energy Energy canNOT be created or destroyed It may be transferred from one object to another ENERGY 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.

Practice: what kind of energy does this climber have?

Rube Goldberg Video Energy Transfer or Transformation? Explain: Energy forms involved Where does the transfer/ transformation take place? http://www.youtube.com/watch?v=qybUFnY7Y8w

Does a windmill represent energy transfer or transformation? Explain: Energy forms involved? Where does the transfer/ transformation take place?

Deep 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?

Do solar panels represent energy transfer or transformation? Explain: Energy forms involved? Where does the transfer/ transformation take place?

Is this an energy transfer or transformation? Explain: Energy forms involved? Where does the transfer/ transformation take place?

Today’s Activity Safety Considerations: Goggles and Lab coats must be warn at all times If 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….

Today’s Activity Safety Considerations: Wash your hands after you leave the lab today DON’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 carefully Be mindful of your movement in the lab and the movement of others.

Teacher Demo

Station 1: Hit metal with string Take two stings that are attached to the metal grate and wrap them around your index finger. Place your fingers in your ears to block out any sound Tap the grate against the table or have partner gently tap the grate with a ruler Write down your observations and give a reason for your results. 1000 ml Pyrex (flame/ hear resistant) Beaker of distilled water with phenaltheline indicator Tiny pieces of sodium metal Latex gloves A knife to cut sodium into small pieces. Safety goggles

Station 2: Burning Magnesium Magnesium & Oxygen CAUTION: Do not look directly at burning magnesium. Position a watch glass near the gas burner. (we would like to use the alcohol burners for this one) 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. Wear goggles 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 octahydrate 17g ammonium thiocyanate (or could use ammonium nitrate or ammonium chloride) 125-ml flask stirring rod Pour 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.

Station 3: Drop a Marble into clay Drop a marble into clay from 30 cm Measure and record the diameter of the crater formed in mm Write down your observations and give a reason for your results

Station 4: Hydrogen peroxide and Potassium Iodide Add 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? Wear gloves and goggles Materials: Watch glass Gas burner Crucible tongs 5 cm Magnesium strips matches

Station 5: HCl and Magnesium Place 20 drops (2 mL) of HCl into one of your test tubes.  Add 2-3 pieces of Magnesium Feel the test tube Record your Observations: What do you see, hear & feel? Wear goggles Materials: Steel ball of known mass Box lined with soft modeling clay Meter stick Ruler

Station 6: Acetic Acid and Sodium Bicarbonate 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 tube Record the new temperature of the mixture. Wear goggles Soapy water 1 M KI Potassium Iodide 300mL 10 %Hydrogen peroxide 2 medium sized Test Tube Ring stand Test tube clamp