Which of the following transition metal ions has the lowest density?

Options

A. Copper
B. Nickel
C. Scandium
D. Zinc

Answer

C

Explanation

(A)=8.95 , (B)=8.95, (C )=3.0 , (D) =7.14
Across the period atomic volume decrease upto copper due poor shielding of d-orbital electrons and addition of extra electrons in inner orbital and then increase inZinc due to interelectronic repulsion in completely filled d-and s-orbitals. Consequently densities increase from Sc to Cu and then decreases in Zn.