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Oxidation States

Introduction: Oxidation states, also known as oxidation numbers, refer to numbers assigned to an element in chemical compounds that represent the number of electrons lost or gained by an atom of that specific element in the compound. Elements like alkali metals and alkaline earth metals often have one positive oxidation state, whereas transition metals tend to have more than one oxidation state.

Oxidation states of individual elements in compounds are based on the premise that compounds overall have an oxidation state of zero. The oxidation states of different element can be solved through applications of algebra. In the compound $"KClO"_3$, K has an oxidation state of +1, Cl's oxidation state is unknown, and O's oxidation state is -2. Because there is 1 atom of potassium, 1 atom of chlorine, and 3 atoms of oxygen atoms, the total oxidation state of K is +1, the total oxidation state of Cl is x, and the total oxidation state of O is -2 x 3, or -6. Based on the fact that the total oxidation state is zero, solving for Cl's oxidation state, we get 1 + x + -6=0, or x=+5. Unknown oxidation states can be found by setting the total oxidation state equal to zero, multiplying oxidation states of elements by the number of atoms of that element, and solving for the unknown oxidation state.

Oxidation states often have important consequences when it comes to the physical properties of specific elements. For example, diamagnetic substances have only paired electrons and repel electrons weakly, leading to a lack of magnetism. Paramagnetic substances, on the other hand, have at least one unpaired electron, leading to magnetism in the presence of a magnetic field.

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