Which of the following does not represent the correct order of the properties indicated

Options

(a) Ni²⁺> Cr²⁺> Fe²⁺> Mn²⁺(size)
(b) Sc > Ti > Cr > Mn (size)
(c) Mn²⁺ > Ni²⁺ (d) Fe²⁺> CO²⁺> Ni²⁺> Cuv(unpaired electron)

Correct Answer:

Ni²⁺> Cr²⁺> Fe²⁺> Mn²⁺(size)

Explanation:

In a period on moving left to right ionic radii decreases