About oxidation numbers...?

Question

After scanning around some previous questions, is an element's Oidation# the same as its Valence Electron#?

Answer 1

not all of the time. In the 1st and second group, aka the alkali metals and the alkali earth metals, they will. but it means what the apparent charge is for an atom in a compound. To find it out easily, you have to criss-cross the number in a binary compound to find it out. ie CO2. put the 2 from the carbons as the oxidation state of the oxygen, and the 1 from the oxygen as the oxidation state of the carbons. to determine the apparent charge, all you have to do is find out which element is more electronegative. some rules for oxidation numbers are that oxygen always gets a -2 charge, except in peroxides, aka H2O2, group 1 and 2 metals get +1 and +2 charges accordingly. all halogens get -1 as a charge. look it up sunshine.

Answer 2

gridagent,

No, they are not the same. An oxidation state, or oxidation number, is a bookeeping device that is used to assign aproximate charges to different atoms in a compound. The number of valence electrons that an atom has is determined by its place in the periodic table. Often, for single atoms at either the left or right edge of the periodic table, the two will happen to be the same. But this is just because of the very simple nature of the bonding in these situations. Looking at a couple examples may help you see the difference:

Sodium (Na) is in the first column of the periodic table, and therefore has 1 valence electron. Since sodium loses this electron so easily, and it is the ONLY one that it has available to lose, sodium will always form a Na+ ion in all of its compounds, its oxidation state in all of those compounds is therefore +1.

Now, take iron (Fe). Iron is in column 8 of the periodic table, so a neutral iron atom has 8 valence electrons. But when iron forms compounds, it NEVER loses all 8 of these electrons, it only loses 2 or 3, to become either Fe2+ or Fe3+. So the possible oxidation states for iron are +2, and +3.

So basically just think of an oxidation state as a charge that is specific to the compound that the atom is in, and the number of valence electrons as a consequence of the elements position in the periodic table. Hope this helps.

Answer 3

No. Valence electrons can be determined from the periodic table. A neutral atom or ions have a determined number of valence electrons that does not change. With oxidation numbers, that is a measure of how willingly the atom gives up electrons (compare to reduction number) For example, Flourine has 7 valence electrons and and always has an oxidation number of -1. Oxygen is the next most electronegative element and is usually a -2 (it's -1 in H2O2, and +1 when bonded with Flourine). Metals usually have a positive oxidation number not always corresponding to the number of valence electrons.

Answer 4

No. Oxidation numbers are determined by the number of electrons that are capable of being donated accepted, or shared. This is caused by the availability of electron orbitals, and unpaired electrons. This is also why each element may have the ability to have different oxidation numbers. For instance if two paired electrons split into two individual unpaired electrons, it will have a tendancy to bond two more times.

Answer 5

no
oxidation number is a "counting system". It is used to help keep trac of oxidatin of elements and molecules. This often gets confused with valence electrons but they are no the same.
Practice assigning oxidation numbers and you will see how usefull they are and ho very differnt they are from valence electrons