1. Two Men walk into a Bar The first guy says, “I’ll have some H 2 0.” The second guy says, “I’ll have some H 2 O too.” The second guy dies.

2. Two Men walk into a Bar The first guy says, “I’ll have some H 2 0.” The second guy says, “I’ll have some H 2 O too.” The second guy dies. H2O2H2O2 H2OH2O vs Homophone

3. Chemical Formula: H2OH2O A Chemical Formula tells you what elements a substance is made up of and in what proportion. 3 Chemical Formula for Water

4. Chemical Formula: H2OH2O A Chemical Formula tells you what elements a substance is made up of and in what proportion. 4 Chemical Formula for Water Water is a combination of the elements Hydrogen and Oxygen There are two Hydrogen atoms and one Oxygen atom. RULE: a subscript applies to what is directly in front of it.

5. Carbon Dioxide CO 2 5 RULE: a subscript applies to what is directly in front of it. CarbonOxygen 1 Atom2 Atoms

6. Calcium Hydroxide Ca(OH) 2 6 RULE: a subscript applies to what is directly in front of it. In this case it applies to everything in the parenthesis. CalciumOxygenHydrogen 1 Atom2 Atoms

7. Calcium Hydroxide Ca(OH) 2 7 RULE: a subscript applies to what is directly in front of it. We can visualize it by imagining there are two Hydroxides (OH) attached to one calcium atom. CalciumOxygenHydrogen 1 Atom2 Atoms OH Ca OH

8. Chemical Formula: Sugar/Sucrose C 12 H 22 O 11 8 12 Carbon atoms 22 Hydrogen atoms11 Oxygen atoms

9. Ammonia: 2NH 3 RULE: a whole number coefficient at the front of a formula applies to EVERYTHING after it. NitrogenHydrogen 2 Atoms6 Atoms

10. Ammonia: 2[NH 3 ] RULE: a whole number coefficient at the front of a formula applies to EVERYTHING after it. You can think of it as there being brackets or parenthesis around everything after the leading coefficient. The two means you have two molecules of Ammonia (NH 3 ) NitrogenHydrogen 2 Atoms6 Atoms

11. Ammonia: 2[NH 3 ] RULE: a whole number coefficient at the front of a formula applies to EVERYTHING after it. Another way to visualize it is by writing the chemical formula twice. NitrogenHydrogen 2 Atoms6 Atoms NH 3

12. Putting Both Rules Together: 2Ca 3 (PO 4 ) 2 CalciumPhosphorousOxygen 6 Atoms4 Atoms16 Atoms Calcium Phosphate

13. 2Ca 3 (PO 4 ) 2 Ca 3 (PO 4 ) 2 Ca 3 PO 4 Ca 3 PO 4 BREAK IT DOWN

14. 2Ca 3 (PO 4 ) 2 IGNORE THE 2

15. 2Ca 3 (PO 4 ) 2 IGNORE THE 2

16. 2Ca 3 (PO 4 ) 2 IGNORE THE 2 COUNT ATOMS

17. 2Ca 3 (PO 4 ) 2 IGNORE THE 2 COUNT ATOMS 3 Calcium atoms 2 Phosphorous atoms 8 Oxygen atoms

18. 2Ca 3 (PO 4 ) 2 COUNT ATOMS 3 Calcium atoms 2 Phosphorous atoms 8 Oxygen atoms Apply the 2 by doubling everything 6 Calcium atoms 4 Phosphorous atoms 16 Oxygen atoms

19. 1.Nitrous Oxide N 2 O 2.Carbon TetraFluoride CF 4 3.Sulfuric Acid H 2 SO 4 4.Water 3H 2 0 5.Baking Soda 2NaHCO 3 6.Calcium Nitride 3Ca 3 N 2 7.Ammonium Nitrate NH 4 NO 3 8.Indigo C 16 H 10 N 2 O 2 9.Aluminum Acetate 3Al(C 2 H 3 O 2 ) 3 10.Aluminum Sulfate 4Al 2 (SO 3 ) 3 Counting Atoms ASSIGNMENT