Why is the number of valence electrons associated with the oxidation number of the element?

1 Answer
Jun 12, 2017

Answer:

Why, because we conceive of the oxidation number as the number of electrons GAINED or RECEIVED by an atom upon chemical reaction.

Explanation:

And oxygen, which as an element has a high nuclear charge (i.e. it comes to the right of the Periodic Table as we face it), tends to accept electrons.........

Guidelines for assigning oxidation numbers are as follows......

#1.# #"The oxidation number of a free element is always 0."#

#2.# #"The oxidation number of a mono-atomic ion is equal"# #"to the charge of the ion."#

#3.# #"For a given bond, X-Y, the bond is split to give "X^+# #"and"# #Y^-#, #"where Y is more electronegative than X."#

#4.# #"The oxidation number of H is +1, but it is -1 in when"# #"combined with less electronegative elements."#

#5.# #"The oxidation number of O in its"# compounds #"is usually -2, but it is -1 in peroxides."#

#6.# #"The oxidation number of a Group 1 element"# #"in a compound is +1."#

#7.# #"The oxidation number of a Group 2 element in"# #"a compound is +2."#

#8.# #"The oxidation number of a Group 17 element in a binary compound"# #"is -1."#

#9.# #"The sum of the oxidation numbers of all of the atoms"# #"in a neutral compound is 0."#

#10.# #"The sum of the oxidation numbers in a polyatomic ion"# #"is equal to the charge of the ion."#

And so when elemental oxygen reacts with say carbon, we conceive that the 2 oxygen atoms accept 2 electrons, and that carbon atom donates two electrons...............

#stackrel(0)C(s)+stackrel(0)O_2(g)rarrstackrel(-II)O=stackrel(+IV)C=stackrel(-II)O(g)#

As always the sum of the oxidation numbers of the elements in a compound or ion, is equal to the charge of the compound or ion, and here the #CO_2# product is neutral.