Covalent Bonds, the Octet Rule, Octet Rule exceptions and the Periodic Table
Dr. Walt Volland revised July 31, 2012 all rights reserved ©
octet rule says "Main-group
elements lose, gain or share electrons
in such a way as to achieve an outer shell with eight electrons, ns2np6
that matches the nearest rare-gas (noble-gas) electron configuration."
Octet rule exceptions:
The octet rule really applies
to a limited number of elements in row 2 of the periodic table; C, N, O and F.
Exceptions to the octet rule occur regularly for row 3 and greater.
These elements with open "d" subshells like phosphorus and sulfur do not always follow the rule. Examples of octet rule "violations" are SF6 and PCl5.Use the octet rule to predict the number of covalent bonds normally formed by phosphorus, P. Click for answer