An element among the following that shows the maximum number of oxidation states is:

1. Cr

2. Fe

3. Mn

4. V

Match the following aspects with the respective metal.

               Aspects                                    Metal

(a) The metal which reveals a       (i) Scandium
     maximum number of
     oxidation states

(b) The metal although placed       (ii) Copper 
      in 3d block is considered
      not as a transition element

(c) The metal which does not         (iii) Manganese 
     exhibit variable oxidation states

(d) The metal which in +1             (iv) Zinc 
     oxidation state in aqueous
     solution undergoes
    disproportionation

Select the correct option :

(1) (a)-(i) (b)-(iv) (c)-(ii) (d)-(iii)

(2) (a)-(iii) (b)-(iv) (c)-(i) (d)-(ii)

(3) (a)-(iii) (b)-(i) (c)-(iv) (d)-(ii)

(4) (a)-(ii) (b)-(iv) (c)-(i) (d)-(iii)

Gadolinium (atomic number 64) belongs to the 4f series.
The correct electronic configuration of gadolinium among the following is:

\(1. (X e) 4 f^{7} 5 d^{1} 6 s^{2} \)

2. \( (X e) 4 f^{6} 5 d^{2} 6 s^{2}\)

3. \((X e) 4 f^{8} 6 d^{2}\)

4. \((X e) 4 f^{9} 5 s^{1}\)

The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of the transition element, which shows the highest magnetic moment.

A pair of ions that have the same electronic configuration among their constituent species is:

1. \(Sr^{3+}, Cr^{3+}\)
2. \(Fe^{3+}, Mn^{2+}\)
3. \(Fe^{3+}, Co^{3+}\)
4. \(Cr^{3+}, Fe^{3+}\)

Which transition element does not exhibit variable oxidation states?

1. Manganese (\(Mn\))
2. Chromium(\(Cr\))
3. Scandium(\(Sc\))
4. Iron(\(Fe\))