# Why are oxidation states such a fundamental quantity for elements?

Why is it that there are fixed oxidation states for most elements out there, with no to very rare exceptions?

I was taught that oxidation state is a totally artificial concept we have invented for book-keeping purposes. How is it that its applicable so widely? I understand the case of formal charges, because that is what keep into consideration when making bonds in the first place.

But oxidation state is somewhat arbitrary, because we don't think about electronegativity when we are making bonds. So can someone help me understand the intuitive reason behind it, its been bothering me for months now?

• In the age of electronic transactions, your money is a totally artificial concept. It doesn't correspond to any physical reality. Yet still it is immensely useful, and of vital importance for many. Oxidation states are much like that. – Ivan Neretin Mar 14 '17 at 8:04
• @IvanNeretin I get that somewhat. But I don't see why we can assign fixed oxidation states to most elements present? Why are their compounds found only in certain fixed oxidation states? – Sawarnik Mar 14 '17 at 8:08
• It is not that "elements are found in such-and-such states". It is that "we can assign", and we most surely can. Indeed, we could have assigned them differently; that doesn't matter much. As long as the oxidation states of all atoms in a compound sum up to 0, it would still be the same useful tool. – Ivan Neretin Mar 14 '17 at 8:18
• Many common oxidation states correspond to stable electron configurations for the atom. For example, many transition metals exhibit a $+2$ oxidation state because it is favorable to lose their valence s electrons. – Tyberius Mar 14 '17 at 20:20