Ionic and Covalent Bonds. Ionic Bonds. When an atom has less than 8 valence electrons in its outer shell, it will gain or lose electrons to become more stable. First outer shell = full with 2 valence electrons Every other shell = full with 8 valence electrons . Ionic Bonds.
its outer shell, it will gain or lose electrons to become more stable.
(left with a positive charge after giving away its valence electron)
Ex. Group 17 has 7 valence electrons, can easily gain 1 more to have a full outer shell
- Cl has an oxidation number of 1- because it gains a negative charge when it completes it’s outer shell
Ionic Bond between Na and Cl:
Ex. Carbonate ion (CO32-) can bond with another ion of an opposite charge, Ca2+
_charges cancel out, forming CaCO3
Use the names of the elements and change the 2nd element’s ending to –ide
-Usually use the first two elements and change the second element’s ending to -ate
C has 4 valence electrons, needs to gain 4
O has 6 valence electrons, needs to gain 2
Cl has 7 valence electrons, bonds with another Cl to share 1 valence electron. Each atoms now has a full outer shell (8).
1 pair of shared valence electrons: Cl - Cl ; Cl2