Metallic radii of some transition elements are given below. Which of these elements will have the highest density -
`{:("Element",Fe,Co,Ni,Cu),("Metallic radii (pm)",126,125,125,128):}`

Options

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

Answer

D

Explanation

Density `=("Mass")/("Volume")`. On going from left to right along the series of elements given here, atomic mass increases and ionic radii decreases and hence, volume decreases (with the exception of Cu which has slightly greater atomic radius than Ni). Increase in mass in case of Cu dominates over small increase in volume. So Cu has the highest density.