The range of oxidation states an element can exhibit is due to the involvement of the inner shell electrons in bonding, especially for transition metals. These elements have incompletely filled d orbitals which can participate in bonding. The flexibility in the number of electrons that can be used from these d orbitals for bonding results in the variable oxidation states. For instance, manganese can exhibit oxidation states from +2 to +7 due to the varied involvement of its d electrons.

The oxidation state of a monoatomic ion is equal to the charge on the ion. This is because the ion, being monoatomic, contains only one type of atom, and its charge arises from the loss or gain of electrons. For instance, Na+ has an oxidation state of +1 as it has lost one electron, whereas O^2- has an oxidation state of -2 as it has gained two electrons.

Yes, oxidation states can be fractional, but this is typically an average value across several atoms in a compound rather than a true depiction of electron distribution. A common example is superoxides where oxygen has an oxidation state of -1/2. In KO₂, potassium superoxide, each oxygen atom doesn't individually have a -1/2 charge, but when considering the compound as a whole and distributing the charges, the average oxidation state for oxygen becomes -1/2.

For elements in the s and p blocks, the oxidation state can often be predicted from the group number. Elements in Group 1 (alkali metals) generally have an oxidation state of +1, while those in Group 2 (alkaline earth metals) have +2. For the p block elements, the oxidation state can be the group number minus ten. For example, Group 15 elements like nitrogen typically have an oxidation state of -3, while Group 17 elements (halogens) have an oxidation state of -1. However, there are exceptions and some elements in these groups can display multiple oxidation states.

Multiple oxidation states can be determined by considering the rules of assigning oxidation states and the nature of the other elements present in the compound. For instance, in transition metals which often exhibit multiple oxidation states, the type and number of ligands or atoms it's bound to can give clues. For instance, iron in FeCl₂ has an oxidation state of +2, whereas in FeCl₃, it has an oxidation state of +3. However, determining exact values might require knowledge of the compound's structure or advanced techniques like X-ray crystallography.