1. Molecular Compounds and Covalent Bonds SNC2D

2. Terms to Know ● A covalent bond is formed when elements share electrons to make a bond. ● A molecular compound is formed from covalent bonding atoms ● Typically form between two non-metals

3. H How Covalent Bonds Form C H H H

4. H C H H H

5. Formulas for Molecular Compounds 1. Write symbols with the non-metal that is further on the left of periodic table first (it will be acting as the cation), and then the one on the right second (it will be acting as the anion) 1. Write the combining capacity for each element over the symbol 1. Use “cross over” method and reduce numbers to lowest ratio C Cl 41 CCl 4 Naming molecular compounds can be tricky. There will be exceptions to the rule, such as hydrogen peroxide H 2 O 2

6. Naming Molecular Compounds ● Cation first, anion second ● Change ending of anion to “ide” ● Use prefixes to identify the number of atoms o mono, di, tri, tetra, etc. o Don’t use mono for a cation o The "o" or "a" ending of the prefix is omitted if the cation or anion name starts with an "o" or "a“ (incorrect → monooxide) CCl 4 carbon tetrachloride

7. More Examples nitrogen monoxideNO silicon dioxideSiO 2 carbon monoxideCO sulfur trioxideSO 3 phosphorus pentabromidePBr 5 dinitrogen trioxideN2O3N2O3

8. Diatomic Gases ● HOFBrINCl o Hydrogen (H 2 ) o Oxygen (O 2 ) o Fluorine (F 2 ) o Bromine(Br 2 ) o Iodine (I 2 ) o Nitrogen(N 2 ) o Chlorine(Cl 2 )