(ii) Name the element which shows only +3 oxidation state. Why do transition metals have variable oxidation states? (ns) and (n -1) d electrons have … Delhi 2014) Answer: The variability of oxidation state of transition elements is due to incompletely filled d-orbitals and presence of unpaired electrons, i.e. Oxidation state of an element is defined as the degree of oxidation (loss of electron) of the element in achemical compound. The energy difference between these orbitals is very less, so both the energy levels can be used for bond formation. Properties All transition metals except Sc are capable of bivalency. i know that-arises from the similar energies required for removal of 4s and 3d electrons. Transition elements exhibit a wide variety of oxidation states in their compounds. Solution for (a) Why do transition elements show variable oxidation states? The 4s electrons are first used and then 3d electrons. Why do transition elements show variable oxidation states? Reason: Close similarity in energy of 4s and 3d electrons. The valence electrons of these elements enter d-orbital. Oxidation states, (aka oxidation numbers), are numbers that show how many electrons the element would lose or gain if it were to bond to other atoms. For example: manganese shows all the oxidation states from +2 to +7 in its compounds. These elements show variable oxidation state because their valence electrons in two different sets of orbitals, that is (n-1)d and ns. The transition elements have outer electrons that occupy a very large shell. (i) Name the element showing maximum number of oxidation states among the first series of transition metals from Sc (Z = 21) to Zn (Z = 30). pH has an effect on the redox potential of the reduction of transition metal ions from higher to lower oxidation states. The variable oxidation states shown by the transition elements are due to the participation of outer ns and inner (n–1)d-electrons in bonding. Transition elements are the elements which lie between 's' and 'p' block elements. These elements show variable oxidation state because their valence electrons in two different sets of orbitals, that is (n-1)d and ns. This oxidation state arises from the loss of two 4s electrons. (i) Name the element showing maximum number of oxidation states among the first… There is a great variety of oxidation states but patterns can be found. (Comptt. Why do transition elements show variable oxidation states? Their general electronic configuration is: where n is the outermost shell. • maximum oxidation state rises across the group to manganese • maximum falls as the energy required to remove more electrons becomes very high • all (except scandium) have an M2+ ion Thus, transition elements have variable oxidation states. Manganate (VII) ions, MnO₄⁻, are strong oxidising agents in acidic solution but a weaker oxidising agent in alkaline solution. This is a table that shows each element's outermost electron shell configuration. Except scandium, the most common oxidation state shown by the elements of first transition series is +2.