The highest oxidation state shown by any transition element is +8.

Explanation:

Transition elements are a group of metals in the periodic table that have partially filled d orbitals. These elements exhibit a variety of oxidation states, ranging from +1 to +8. The highest oxidation state shown by any transition element is +8, which is demonstrated by the element Ruthenium (Ru) in the compound RuO4.

Transition Metals:

Transition metals are located in the d-block of the periodic table, specifically in groups 3 to 12. These elements include well-known metals such as iron, copper, zinc, and silver. The d orbitals in these elements can accommodate a maximum of ten electrons, allowing for a wide range of oxidation states.

Oxidation State:

The oxidation state of an element refers to the charge that it carries when it forms compounds. It is determined by the number of electrons that an atom gains, loses, or shares when it combines with other atoms. Transition elements have the ability to exhibit multiple oxidation states due to the presence of their partially filled d orbitals.

Ruthenium and its Highest Oxidation State:

Ruthenium, a transition metal, is known to exhibit a variety of oxidation states ranging from -2 to +8. Its highest oxidation state of +8 is observed in the compound RuO4, known as ruthenium tetroxide. In this compound, ruthenium is bonded to four oxygen atoms, with each oxygen atom having a charge of -2. Since the overall charge of the compound must be zero, ruthenium must have a charge of +8 to balance the negative charges of the oxygen atoms.

Conclusion:

In conclusion, the highest oxidation state shown by any transition element is +8, which is demonstrated by the element ruthenium (Ru) in the compound RuO4. Transition elements, due to their partially filled d orbitals, have the ability to exhibit a wide range of oxidation states, allowing for the formation of various compounds with different charges.