what are valence electrons

Question

anonymous · Answer

the electrons in the outermost shell of an element.

anonymous · Answer

why are they always between 1 and 8

unklerhaukus · Answer

because after eight they form a new shell

anonymous · Answer

outer most shell electrons, usually the halogens have all paired electrons thats why they stable

anonymous · Answer

outer most energy levels are always s or p sublevels, that looks weird

anonymous · Answer

They are between 0 and 8 only for s and p block elements.  Transition metals can easily have more than 8 valence electrons; indeed 18 is more typical.

anonymous · Answer

but no element in periodic table has valence electrons more than 8

anonymous · Answer

No, sorry, @sara12345, that is not correct.  Consider $$[{\rm Mn}({\rm CN})_6]^{4-}$$How many valence electrons are around the manganese atom?  The only plausible answer is 12, because you need 2 for each bond to a CN group.  There are many other examples in transition metal complexes.

I understand what you're saying, but that rule is a simplification, and is really only good for the first two periods of the main group elements.

anonymous · Answer

thnks