2. Activity 20: Modeling Polymers Warm up: Write the reactants and products of the chemical equation below. Is the equation balanced?

3. Balancing Chemical Equations Law of Conservation of Mass- mass cannot be created or destroyed, including during a chemical reaction. If I mix 5 g of lemonade mix with 50 g of water, how many grams will the final product be?

4. Balancing Chemical Equations There must be the same AMOUNT of reactant and product. – The materials can be bonded differently, but the ratio must stay the same.

5. Quest Review Today! Do not forget that the Quest Review session is happening during SDL today! If you received an 11/15 or below, remember that you are required to come today. If you received above an 11/15, it is optional. Bring questions! You are running how this works.

6. Activity 19 Homework Sheet 1. What are 4 ways we can tell if a chemical reaction has occurred? – Color change – Gas given off – Precipitate formed – Temperature change

7. Temperature Change in Reactions A substance can get colder or hotter depending on the reaction. Endothermic reaction- an reaction absorbs/uses the surrounding heat, causing the substance to become cold. Exothermic reaction- a reaction gives off heat to the surrounding area, causing the substance to heat up.

8. Activity 19 Homework Sheet 2. and 3. What were the reactants and products of the chemical reaction in Act. 19? – Reactants: sodium borate and polyvinyl alcohol – Product: jelly ball of polyvinyl alcohol

9. Activity 19 Homework Sheet 4. Law of Conservation of Mass- mass cannot be created or destroyed, even in a chemical reaction.

10. Activity 19 Homework Sheet 5. If there are 6 atoms of hydrogen and 3 atoms of oxygen in the reactants, how many atoms of hydrogen and oxygen will be in the products? 6 hydrogen and 3 oxygen

11. Activity 19 Homework Sheet a.What molecule would form given the reactants below? CO 2 (or a carbon and 2 oxygen) a.What reactants caused this product to form? 1 nitrogen and 3 hydrogens

12. Activity 19 In Case You Missed It... Plastics are a part of a group of chemicals known as polymers, which are made of repeating molecules (called monomers) linked together. – Monomer- “one part” – Polymer- “many parts” The chemical structure of polymers affects their physical properties.

13. Activity 19 In Case You Missed It... Law of Conservation of Mass- mass cannot be created or destroyed. Chemical reaction- when two or more reactants combine chemically to form a new product.

14. Activity 19 In Case You Missed It... There are two types of temperature changes that can happen during a chemical reaction. – Endothermic reaction- a reaction absorbs heat or energy, causing it to feel cold. – Exothermic reaction- a reaction releases heat or energy, causing it to feel hot.

15. Activity 20: Modeling Polymers Please open your books to page B42.

16. Activity 20: Modeling Polymers With the people at your table, create a data table according to step 1 in the procedure. Complete the procedure on page B43 and B44 with those at your table. As you go through the procedure, be sure to record your data!

17. Activity 20: Modeling Polymers How could you have made your model more “solid?”

18. Activity 20: Modeling Polymers Look at #3 of the analysis questions. – Using examples from this and Activity 19, “Designing New Materials,” explain the relationships between a monomer, a polymer, and a cross- linked polymer. Include a sketch to illustrate your explanation.

19. Activity 20: Modeling Polymers In groups of 2 or 3, create a response and diagram to answer all parts of the prompt. You will be presenting your diagrams and responses to the classes. As you do, classmates will be scoring your answer on the scoring guide.

20. Tonight’s Homework Be sure to study for the Quest on Friday! Come to the review session during SDL if you signed up!