Which of the d-block elements has the lowest electronegativity ?

Options

A. Co
B. Ni
C. Cu
D. Zn

Answer

D

Explanation

d-block elements have fairly low values of electronegativity. In 3d-series it generally increases form Sc to Cu with a fall at Zn. However, this increase in electronegativity is much slower because the additional electron is being added to an inner shell which provides relatively good shielding to the outermost ns electrons form the nucleus. Consequently, the elements (Co, Ni and Cu) in the second half of the 3d- series have similar electronegativity. The increasing electronegativity form Sc to Cu impiles that the elements becomne slightly less metallic and this is reflected in the decreasing negative `E^(Theta)(M^(2+)//M` and `M_(3+)//M^(2+))` values.