How systems depend on CARBON and CHEMICAL ENERGY

1. Systems and Scale How systems depend on CARBON and CHEMICAL ENERGY

2. Lesson 5 Activity 1 Explaining what happens when methane burns.

3. Three Questions Poster

4. What happens when methane burns? Where are atoms moving to? Where are atoms moving from? Chemical change Remember: Atoms last forever (so you can rearrange atoms into new molecules, but can’t add or subtract atoms)Energy lasts forever (so you can change forms of energy, but energy units can’t appear or go away) What molecules are carbon atoms in before the change? What other molecules are involved? What molecules are carbon atoms in after the change? What other molecules are produced? What forms of energy are in the reactants? What forms of energy are in the products?

5. Making the Reactant Molecules: Methane and Oxygen The flame of burning methane comes when ethanol (CH4) reacts with oxygen (O2). Make a molecules of methane and oxygen on the reactant side of your Molecular Models poster: • Get the atoms you will need to make your molecules. Can you figure out from the formula for methane how many C, H, and O atoms you will need? • Use the bonds to make models of an ethanol molecule (CH4) and at least 2 oxygen molecules (O2, with a double bond) • Identify the high-energy bonds (C-C and C-H) by putting twisty ties on them. How many high energy bonds does a molecule of methane have? • Compare your molecules to the pictures on the next slide. Are they the same?

6. Photo of reactant molecules: MethaneStart by making the molecules and energy units of the reactants and putting them on the reactants side, then rearrange the atoms and energy units to show the products. Chemical change Remember: Atoms last forever (so you can rearrange atoms into new molecules, but can’t add or subtract atoms) Energy lasts forever (so you can change forms of energy, but energy units can’t appear or go away) Reactants Products

7. Rearranging the Atoms to Make Product Molecules: Carbon Dioxide and Water The flame of burning methane comes when methane (CH4) reacts with oxygen (O2) to produce carbon dioxide (CO2) and water (H2O). Show how this can happen: • The heat of the flame breaks the bonds in the molecules, so their bonds can break. Now they can recombine into carbon dioxide (CO2) and water vapor (H2O). Make as many of these molecules as you can from one methane molecule and oxygen. • Figure out numbers of molecules: • How many O2 molecules do you need to combine with one methane molecule? • How many CO2 and H2O molecules are produced by burning one molecule? • Remember, atoms last forever. So you can make and break bonds, but you still need the same atoms. • Remember, energy lasts forever. What forms of energy do the twisty ties represent now? • Compare your molecules to the pictures on the next slide. Are they the same?

8. Photo of product molecules CO2 and H2O (carbon dioxide and water)Start by making the molecules and energy units of the reactants and putting them on the reactants side, then rearrange the atoms and energy units to show the products. Chemical change Remember: Atoms last forever (so you can rearrange atoms into new molecules, but can’t add or subtract atoms) Energy lasts forever (so you can change forms of energy, but energy units can’t appear or go away) Reactants Products

9. Comparing photos of reactant and product moleculesStart by making the molecules and energy units of the reactants and putting them on the reactants side, then rearrange the atoms and energy units to show the products. Chemical change Remember: Atoms last forever (so you can rearrange atoms into new molecules, but can’t add or subtract atoms) Energy lasts forever (so you can change forms of energy, but energy units can’t appear or go away) Reactants Products

10. Writing a Chemical Equation • Chemists use chemical equations to show how atoms of reactant molecules are rearranged to make product molecules • Writing the equation in symbols: Chemists use an arrow to show how reactants change into products:[reactant molecule formulas] product molecule formulas] • Saying it in words: Chemists read the arrow as “yield” or “yields:”[reactant molecule names] yield [product molecule names] • Equations must be balanced: Atoms last forever, so reactant and product molecules must have the same number of each kind of atom • Try it: can you write a balanced chemical equation to show the chemical change when methane burns?

11. Chemical equation for ethanol burning CH4 + 2O2 CO2 + 2 H2O (in words: methane reacts with oxygen to yield carbon dioxide and water)

12. What happens when ethanol burns? Where are atoms moving to? Where are atoms moving from? Chemical change Remember: Atoms last forever (so you can rearrange atoms into new molecules, but can’t add or subtract atoms)Energy lasts forever (so you can change forms of energy, but energy units can’t appear or go away) What molecules are carbon atoms in before the change? What other molecules are involved? What molecules are carbon atoms in after the change? What other molecules are produced? What forms of energy are in the reactants? What forms of energy are in the products?

13. Lesson 5 Activity 2 Finding Organic and Inorganic Materials

14. Why do some things burn and other things do not burn?Why does ethanol behave more like wood than water? Driving question

15. Why does ethanol behave more like wood than water? ZOOMING INTO FUELS

16. What we see… Macroscopic Scale ETHANOL WATER WOOD

17. Zooming out… Large Scale WATER (ocean and cloud) Petroleum WOOD (Forest)

18. Zooming in… Microscopic Scale WATER (a single droplet) ETHANOL (a single droplet) WOOD CELLS

19. Zooming in… Atomic-molecular Scale Water molecule (H2O) Ethanol molecule (C2H6O) Cellulose (C6H10O5)m ( wood is a mixture of many large and small molecules, including cellulose)

20. What ATOMS are found in these materials? Water molecule (H2O) Ethanol molecule (C2H6O) Cellulose (C6H10O5)m

21. What ATOMS are found in these materials? ATOMS FOUND IN EACH MOLECULE: Water: Hydrogen, Oxygen Ethanol: Hydrogen, Oxygen, Carbon Wood: Hydrogen, Oxygen, Carbon Water molecule (H2O) Ethanol molecule (C2H6O) Cellulose (C6H10O5)m

22. What BONDS are found in these materials? Water molecule (H2O) Ethanol molecule (C2H6O) Cellulose (C6H10O5)m

23. What BONDS are found in these materials? BONDS FOUND IN EACH MOLECULE: Water: H-O Ethanol: H-O, C-O, C-H, C-C Wood: H-O, C-O, C-H, C-C Water molecule (H2O) Ethanol molecule (C2H6O) Cellulose (C6H10O5)m

24. What BONDS are found in these materials? Chemical Energy Energy found in the bonds of molecules. C-C and C-H bonds means molecules have usable chemical energy. So which materials have chemical energy? Water molecule (H2O) Ethanol molecule (C2H6O) Cellulose (C6H10O5)m

25. What makes something organic?ORGANIC AND INORGANIC MATERIALS

26. Materials That Do NOT Burn Materials That Burn WATER PROPANE SALT CARBON DIOXIDE BUTANE WOOD OXYGEN NITROGEN ETHANOL

27. What makes these burn? How are these different? WATER PROPANE SALT CARBON DIOXIDE BUTANE WOOD OXYGEN NITROGEN ETHANOL

28. Water, Ethanol, and Wood Ethanol is chemically similar to wood ETHANOL WATER WOOD

29. MATTER AND ENERGY • Every molecule has both ATOMS and BONDS ATOMS TELL YOU ABOUT MATTER BONDS TELL YOU ABOUT ENERGY

30. ORGANIC INORGANIC --means the molecule has C-C and C-H bonds --means the molecule does not have C-C and C-H bonds

31. What Makes Up Living Things? Average Human Average Apple Average Chicken Inorganic: Water, minerals; Organic: carbohydrates, fats, proteins

32. Lesson 5 Activity 3 Explaining burning of other materials

33. Methane Butane Ethanol Propane Octane Burning materials