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Check Your Answers…

Check Your Answers…

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Check Your Answers…

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  1. Check Your Answers…

  2. CyberEd • 1. Create a long list of Examples of Chemical Reactions as you go through thelesson. • Fireworks, rusting, combustion, electrolysis, brushing teeth, leaves changing color on the fall, glow sticks, compost, foods spoiling, digestion, plants growing, • Copy and complete the sentences with blanks… • 2. A chemical reaction is a process where one or more substances change to become one or more new substances. • 3. Mass, color and boiling point are physical properties. • 4. List and give examples of the 5 signs of a chemical reaction. • A change in color • A change in energy – Exothermic or Endothermic • A change in odor • Gas forms • Solid forms - precipitate • 5. Boiling water is a physical change. • 6. Vinegar added to baking soda is a chemical change because we get bubbles of carbon dioxide a new product. • 7. Freezing water is a physical change because we still have water. • 8. Dihydrogen monoxide is water. • 9. Subscripts are the lower number in a chemical formula that tell how many atoms are in the molecule. Like H2O

  3. H H C H H O O C 11. Draw and label a methane molecule. 12. Draw and label a carbon dioxide molecule. 13. Write a chemical equation for making salt. Label the reactants and products. 2Na + Cl2 2NaCl Reactants Products 14. Coefficients are thelarge numbers in front of formulas that help us balance an equation 15. The Law of Conservation of Mass states that… Matter is neither created nor destroyed in chemical reactions. 16. This means the atoms of Reactant = the atoms of Product

  4. 17. We can never change the subscript number to balance a reaction because… It would change the type of molecule for example CO is toxic carbon monoxide and CO2 is carbon dioxide H2O is water and H2O2 is Hydrogen peroxide 18. Chemical reactions like people dancing because… People can change partners during a dance. In a chemical reaction atoms come apart and recombine to make new molecules. 19. In exothermic reactions heat exits the reaction. 20. In endothermic reactions heat is absorbed. 21. Pause so that you can record the chemical equation for photosynthesis. 6CO2 + 6H2O + Light Energy C6H12O6 + 6O2 6 carbon dioxide molecules and 6 water molecules in the presence of sunlight in green plants will yield or make one sugar molecule and 6 oxygen molecules

  5. List the 5 factors that affect the speed of a chemical reaction and give an example for each. • Use an Inhibitors to slow a reaction down… • such as paint that slows the rusting of metals • Change Temperature • such as heating the glow stick to make it brighter • Concentration of Reactants • such as using a whole box of baking soda and a big bottle of vinegar to make a huge pile of carbon dioxide bubbles. • Use a Catalyst to speed a reaction up… • like salt and water caused the rust to happen fast in a hand warmer. • Change the Surface Area • like when we tore aluminum foil into small pieces to expose more atoms to the other reactants • also we used iron powder instead of a solid piece of iron to make the rust reaction go faster