1. Chemical Equations

2. Diatomic Gases
Elements that bond to another atom of itself to become stable
H2 , N2 , O2 , F2 , Cl2 , Br2 , I2
More on Molecules

3. Write the following as a Chemical Equation
Hydrogen gas reacts with oxygen gas to produce water H2 + O2 
H2O
What’s wrong with this equation?
It appears as if we lost an oxygen atom

4. Balancing Equation Blogs
Balancing Equations
Balancing Equation Blogs

5. 2 H2 +  O2
H2O 2
Reactants
Products
H  2 4
H  2 4
O  2
O  1 2

6. Balancing Equations
Use coefficients (# in front of formula) to balance
Never change subscripts to balance

7. Practice These Equations

8. Tips for Balancing Balance elements one at a time
Balance elements that only appear once on each side of the 
Balance hydrogen and oxygen last if possible
Use the smallest coefficients possible (reduce)
Balance polyatomic ions as a unit if they appear on both sides of the 

9. Balancing Quiz