1. Warm Up What is a chemical reaction? How do you know there has been a chemical reaction?

2. Notes: Chemical reactions- are when 2 or more COMPONDS combine chemically or break chemical bonds. Chemical reactions are written using the Element Symbols and any possible subscripts or coefficients.

3. Reactants → Products The chemicals that go into a reaction are called reactants. The chemicals that come out are called products. The arrow (→) means “yields” or “makes” or “produces”.

4. Let’s Label: 2Na + Cl 2 2NaCl productsreactants

5. 2Na + Cl 2 2NaCl productsreactants Coefficient

6. 2Na + Cl 2 2NaCl Coefficient is the BIG number in front. the number of molecules that are needed to balance it

7. More details… Examples of word equations are Hydrogen + Oxygen → Water Sodium + Chlorine → Sodium chloride Zinc + Hydrochloric acid → Zinc chloride + hydrogen gas In all chemical reactions mass is conserved as reactants are transformed into products by the rearrangement of atoms.

8. Let’s watch a chemical reaction that is tasty! http://www.sciencekids.co.nz/vi deos/chemistry/chocolate.htmlhttp://www.sciencekids.co.nz/vi deos/chemistry/chocolate.html

9. What does a chemical reaction look like? Is the same # of atoms on the Product side? Reactants: Carbon- 3 Hydrogen- 8 Oxygen – 10

10. How do you say it? 2 HCl + 2 Na → 2 NaCl + H 2 You would say "two HCl plus two Na yields two NaCl and H two."

11. Let’s practice: Work with your partner to complete the worksheet Keep it! We will check it!

12. Bill Nye’s chemical reaction video! http://www.youtube.com/watch?v=PlwuxpMh8nk

13. Homework: Do your very best! Check over your work. Review power points on my website! Due next class. Please complete at home!