Generally, what does a complete valance shell hold?
1 Answer
Mar 29, 2017
Generally, we don't know how many "valance" electrons, unless we know what period we're talking about...
- Period 1 has access to only the
#1s# orbital at the moment, e.g. two valence electrons max. - Period 2 has access up to the
#2s# and#2p# orbitals at the moment, e.g.#2 + 6 = ?# valence electrons max. - Period 3 feels free to ignore the so-called "octet rule" when it comes to phosphorus, sulfur, and chlorine. They arbitrarily include the
#3d# orbitals when they need to, and thus have#18# valence electrons max. Otherwise, period 3 has the same max as period 2... - Periods 4 and 5 have the same max as period 2, EXCEPT for the transition metals, which have a max of
#18# (why?). - Periods 6 and 7 are stated by the periodic table to include the
#f# -block, i.e. the max number of valence electrons has increased again to#32# (how many#f# orbitals are there for a given#n# ?).
Thus, the VERY general and NOT AT ALL ABSOLUTE pattern is