why is it possible for sulfur to have more than 8 valance electrons(exception of October rule) but oxygen can not even though they are in the same group?​

Answer is in the file below

tinyurl.com/wpazsebu

in theory, limestone is composed principally of the compound calcium carbonate - caco3, but in reality this compound is deposited in conditions involving a number of other compounds as impurities so it ends up being a mixture of many compounds.

hope this : -)

tony (lordcaos066)