1. (2.3) CHEMICAL EQUATIONS (p144-145)

2. Recall: Word Equation A word equation - states what reacts and what is produced - uses words instead of formulas to describe a chemical reaction

3. Word Equation-Examples ex 1: magnesium + oxygen  magnesium oxide what reacts what is produced (reactants) (products)

4. Word Equation-Examples ex 2: zinc + hydrochloric acid  hydrogen + zinc chloride what reacts what is produced (reactants) (products)

5. Chemical Equation A chemical equation uses chemical symbols and formulas to represent the reactants and products in a chemical reaction

6. Chemical Equation From the word equation you can now write a chemical equation: ex: a) sodium chloride  sodium + chlorine (word equation) b) NaCl  Na + Cl 2 (chemical equation)

7. Chemical Formulas The chemical formulas of most elements are written simply as the symbol in the periodic table ex: magnesium, Mg sodium, Na  But there are some elements that contain more than one atom.  For a list, see Table 2.9 p147

8. Chemical Formulas Textbook p 147

9. CLASSWORK Copy Table 2.9 (pg. 147) into your notes pg.147 “Learning Check” # 1 - 4

10. HOMEWORK “Chemical Reactions and Chemical Equations” Worksheet