Molecular Notation and Chemical Equations

1. 8th Grade Science Mrs. Sassaman All images are from www.Chem4kids.com Molecular Notation and Chemical Equations

2. Molecular Notation Chemical symbol for Hydrogen Chemical symbol for Oxygen H2O No number mean 1 atom of Oxygen Means 2 atoms of Hydrogen 3 total atoms

3. Molecular Notation Chemical symbol for Hydrogen Chemical symbol for Carbon CH4 5 total atoms Means 4 atoms of Hydrogen No number means 1 atom of Carbon

4. Molecular Notation Chemical symbol for Oxygen Chemical symbol for Carbon CO2 3 total atoms Means 2 atoms of Oxygen No number means 1 atom of Carbon

5. Molecular Notation Chemical symbol for Oxygen Chemical symbol for Sodium NaOH Chemical symbol for Hydrogen 3 total atoms No number means 1 atom of Hydrogen No number means 1 atom of Sodium No number means 1 atom of Oxygen

6. Chemical Equations 2Na + Cl2 2NaCl 2H2 + O2 2H2O

7. Chemical Equations PRODUCTS REACTANTS 2H2 + O2 2H2O A coefficient shows the number of molecules. A subscript shows how many atoms in a formula. H2 2H2 The arrow says ‘produces’ or ‘yields’ (or ‘turns into’). It always points from reactants to products. H2

8. Chemical Equations Li2O + MgCl2 2LiCl + MgO Li – Lithium – 2 O – Oxygen – 1 Mg – Magnesium – 1 Cl – Chlorine - 2 Li – Lithium – 2 O – Oxygen – 1 Mg – Magnesium – 1 Cl – Chlorine - 2 2AlCl3 + 3Na2CO3 Al2(CO3)3 + 6NaCl Al – Aluminum – 2 Cl – Chlorine – 6 Na – Sodium – 6 C – Carbon – 3 O – Oxygen - 9 Al – Aluminum – 2 Cl – Chlorine – 6 Na – Sodium – 6 C – Carbon – 3 O – Oxygen - 9

9. A Model for the Combustion of Methane PRODUCTS REACTANTS CH4 + 2O2 • CO2 + 2H2O