1. Covalent Bonding
Electron Sharing

2. Covalent bonds result from the sharing of e-
Ionic bonds result from the transfer of e-

3. Properties of Covalent Compounds
Made of 2 nonmetals
Low melting points
Low boiling points
Soft and squishy
More flammable than ionic compounds
Do not conduct electricity in water
Are not usually very soluble in water

4. Molecular Orbitals Shared space electrons move in
Created when 2 atomic orbitals overlap

5. Energy
Atoms want the lowest potential energy possible because it is more stable
As 2 atoms come together their potential energy decreases
When energy at lowest point bond forms
Attractive and repulsive forces are balanced

6. Bond Length
Bond length is the average distance between the nuclei of the atoms at lowest potential energy
Its like the atoms are held together by a slinky
The atoms are constantly vibrating so the distance actually changes slightly

7. Bond Energy
The amount of energy required to break the bonds in 1 mol of a chemical compound
Higher bond energy means stronger bonds
Higher bond energy means shorter bond length

8. Kinds of Covalent Bonds
2 types:
Polar covalent -the electrons are not shared equally
Nonpolar covalent- electrons are shared equally
Polar have more ionic character than nonpolar

9. What kind of Bond? 0-0.5 make nonpolar covalent bonds
The difference in electronegativity of the 2 elements determines kind of bond
Differences of:
0-0.5 make nonpolar covalent bonds
make polar covalent
make ionic bonds
Electronegativity difference is not the only way to determine the type of bond, you must also look at the properties of the compound

10. nonPOLAR Covalent Bonds
Electrons equally shared between the atoms
No ionic character

11. Polar Covalent Bonds Ends that have partial + and – charges
Electrons spend more time around the atom with the larger electronegativity
Called dipole molecules
Not ionic because electrons still being shared
Larger polarity (larger difference in electronegativity) means stronger bond (higher bond energy) and shorter bond length
More polar has more ionic character
Bonds

12. Metallic Bonding
Valence electrons attracted to all the other atoms in the sample
Electrons move freely throughout the sample
Allows the conduction of electricity
“sea of electrons”