Question

Metallic radii of some transition elements are given below. Which of these elements will have highest density? [NCERT Exemplar]
(a) Fe
(b) Ni
(c) Co
(d) Cu

Answer 1

Answer:

Option D

Explanation:

Density of an element is equal to mass divided by volume and volume is proportional to radius.

Therefore, density is directly proportional to mass and inversely to the radius.  Among the given options Cu has the highest mass but the radius of Cu is little  greater than Ni. Hence, Ni has a greater density than Cu.

Important Point :

Along 3d series, density of elements continuously increases. Till Ni, it increases very sharply but after Ni, to Zn increases slowly.