Answer the following:
(a) Answer the following questions:
(i) Which element of the first transition series has the highest second ionization enthalpy?
(ii) Which element of the first transition series has highest the third ionization enthalpy?
(iii) Which element of the first transition series has the lowest enthalpy of atomization?
(b) Identify the metal and justify your answer.
(i) Carbonyl M(CO)₅
(ii) MO₃F

(i)Out of all the elements of the first transition series copper has the highest second ionisation enthalpy. After the Loss of first electron from the 4s copper acquires 3d¹⁰ configuration which is stable.

(ii)The trend in the third ionization enthalpies is not complicated by the 4s orbital factor and shows the greater difficulty of removing an electron from the d5 (Mn²⁺) and d10 (Zn²⁺) ions.

(iii) Zinc has the lowest enthalpy of atomization but it is not considered a transition metal as it is the last member of the transition metal series and has a completely filled d-orbital.

(i) It is Fe(CO)_5​ by EAN rule
(ii) MO₃​F is MnO_3​F
In MO₃​F let us assume M=x
x+3×(−2)+(−1)
x=+7
M is in +7 oxidation state so that the given compound is MnO₃​F