2. 4 – Investigate and describe the compounds formed by bonding elements. 3 – Describe why certain elements bond with others. 2 – Use the periodic table to identify the number of protons, neutrons, or electrons in an element. 1 – Identify patterns on the periodic table.

3.  Synthesis – two or more elements combine to make a more complex substance.  Decomposition – Compounds are broken into simpler products.  Replacement – When one element replaces another in a compound

4.  A chemical equation is a short, easy way to show a chemical reaction using symbols instead of words.  A reactant is the substance you have at the beginning of the reaction.  A product is the new substance that formed during the reaction.

5.  The principle of conservation of mass states that in a chemical reaction, the total mass of the reactants must equal the total mass of the products.

6.  Write the equation. › H 2 + O 2 H 2 O  Count the atoms. › H 2 + O 2 H 2 O › 22 2 1

7.  Use Coefficients to Balance Atoms. › 2_H 2 +__ O 2 2_ H 2 O › 4 2 4 2  Look Back and Check › The left and right sides of the equation should be equal.

8. 4 – Investigate and describe the compounds formed by bonding elements. 3 – Describe why certain elements bond with others. 2 – Use the periodic table to identify the number of protons, neutrons, or electrons in an element. 1 – Identify patterns on the periodic table.