The number of oxidation states shown are less in 5d transition series than 4d series. So copper element only can have +1 oxidation state. 4. In 3d series +2 and +3 oxidation states are common and they form stable complexes in these oxidation states. Cu (Z = 29) Electronic configuration is [Ar] 3d 10 4s 2 . For the first row of the d block, there is a small increase in successive ionisation energies; this leads to the formation of metal ions with the same charge for many of the transition metals. (ii) Manganese exhibits the highest oxidation state of +7 among the 3d series of transition elements. 3. It is unique in 3d series having a stable +1 oxidation state. In other series OsO 4 and PtF 6 are formed which are quite stable in higher oxidation state. 2. For ions, the oxidation state is equal to the charge of the ion, e.g., the ion Fe 3 + (ferric ion) has an oxidation state of +3. Mn 2+ (3d 5) is more stable than Mn 4+ (3d 3) is due to half filled stable configuration. Cu (Z = 29) Electronic configuration is [Ar] 3d 10 4s 2. Cu is the only metal in the first transition series (3d series) which shows +1 oxidation state most frequently. The oxidation state of a neutral compound is zero, e.g., Which metal in the 3d series exhibits +1 oxidation state most frequently and why? to Q.9 (ii). (ii) Mn has electronic configuration (Ar) 4s2 3d5 and all the electrons in ‘s’ as well as ‘d’ orbitals can take part in bond formation, therefore, it shows + 7 highest oxidation state. Answer: 1. Free elements (elements that are not combined with other elements) have an oxidation state of zero, e.g., the oxidation state of Cr (chromium) is 0. Mn(25) = [Ar} 3d 5 4s 2. When a 3d transition element shows two different oxidation states that differ by 2 units then the compounds in the lower oxidation state are ionic and the compounds in the higher oxidation state are covalent. (ii) Manganese exhibits the highest oxidation state of+7 among the 3d series of transition elements Answer: (i) Refer Ans. The first transition metal copper exhibits only +1 oxidation state. So copper element only can have +1 oxidation state. The reason why Manganese has the highest oxidation state is because the number of unpaired electrons in the outermost shell is more that is 3d 5 4s 2.. The elctronic configuration of Manganese is. Answer: Manganese is the 3d series transition element shows the highest oxidation state. Usually in +2 and +3 oxidation states, the bonds formed are mostly ionic while in higher oxidation states the bonds formed are covalent. (Delhi 2011) Answer: (i) Because presence of unpaired d electrons, which undergoes d-d transition by absorption of energy from visible region and … The first transition metal copper exhibits only +1 oxidation state. The last element Cu shows +1 and +2 oxidation states only. in 3d transition series which has +3 oxidation state - 30578778 2. Question 29. For example, in the 3d series, first element Sc has only one oxidation state +3 the middle element Mn has six different oxidation states from +2 to +7. 1. It is unique in 3d series having a stable +1 oxidation state. 3. This is because the electronic configuration of Cu is 3d 10 4s 1 and after losing one electron it acquires a stable 3d 10 configuration.