1. Covalent Bonds

2. Why do atoms bond?
Atoms want STABILITY- to achieve a noble gas configuration (octet)
For ionic bonds there is a transfer of electrons to get an octet of electrons
For covalent bonds there is a sharing of electrons to get an octet

3. What is a covalent bond?
Covalent bond - the chemical bond that results from sharing of valence electrons
Occurs with elements close to each other on the periodic table
Between a nonmetal and a nonmetal
Molecule is two or more atoms bonded covalently

4. Examples of Molecules F2 H2O NH3 (ammonia) CH4 (methane)
Notice there are no metals, only non-metals

5. Diatomic Molecules Some atoms do not exist as a single atom
Atoms that exist as two H2, O2, N2, Cl2, Br2, I2, F2
HONClBrIF
Magnificent 7-don’t forget H

6. 3 Types of Covalent Bonds: Single, Double and Triple bonds

7. Strength of Covalent Bond
Several factors control bond strength
Number of shared electrons-the more electrons shared, the shorter the bond,
the greater the bond strength
Size of the atoms

8. Single Covalent Bonds Each atom shares one pair (2 total) of electrons
Longest bond
Weakest bond of the three

9. Double Covalent Bonds
Each atom shares two pairs (4 total) of electrons
Medium length bond
Medium strength bond

10. Triple Covalent Bond
Each atom shares three pairs (total 6) of electrons
Shortest bond
Strongest bond
Carbon and nitrogen can form triple covalent bonds

11. Single, Double & Triple Bonds

12. Covalent Molecule Properties
Tend to be soft solids, liquids, or gases at room temperature
Low melting and boiling points
Poor conductors of heat and electricity
Non-electrolytes – do not conduct electricity in water