1. How do we make larger particles than atoms?

2. SYMBOL- shorthand for one atom of an element SUBSCRIPT- Lower right corner (behind the symbol) Tells you number or atoms for that element If there is no subscript-it means one atom COEFFICIENT- In front of formula Tells you how many molecules you have All elements are multiplied by that number 2O22O2

3. Ba Cl 2 Ba means Barium- If there is no subscript you only have one atom There is a subscript of 2 so this means: you have 2 Chlorine atoms H 2 SO 4 There is a subscript of 2 behind the H so there are 2 Hydrogen Atoms. How many atoms of Sulfur? How many atoms of Oxygen?

4. Ca 3 (PO 4 ) 2 2NaSO 4 There is a coefficient of 2 in front of the whole formula. This means all the elements in the formula are multiplied by 2 NaSO 4 + NaSO 4 When you have a subscript outside parenthesis, you multiply each element INSIDE them by that subscript

5. 2H2O2H2O 3Na 2 SO 4 4Pb(NO 3 ) 2 How many molecules? 2 molecules How many Hydrogens? Oxygens? H=4 O=2 How many molecules? 3 molecules How many Sodiums? Sulfurs? Oxygens? Na=6 S=3 O=12 How many molecules? 4 molecules How many Leads? Nitrogens? Oxygens? Pb=4 N=8 O= 24

6. Ba 3 (PO 4 ) 2 Ba=3 P=2 O=8 Total=13 3CaCl 2 Ca=3 Cl=6 Total: 9 NH 4 C 2 H 3 O 2 N=1 H=7 C=2 O=2 Total=12 Pb(NO 3 ) 2 Pb=1 N=2 O=6 Total: 7 K 2 CO 3 K=2 C=1 O=3 Total=6 Na 2 CrO 4 Na=2 Cr=1 O=4 Total: 7 4Al 2 (CO 3 ) 3 Al=8 C=12 O=36 Total=56 2(NH 4 ) 2 Cr 2 O 7 N=4 H=16 Cr=4 O=14 Total: 38