Question

The increasing order of the density of alkali metals is

• A. Li < K < Na < Rb < Cs
• B. Li < Na < K < Rb < Cs
• C. Cs < Rb < Na < K < Li
• D. Cs < Rb < K < Na < Li
• E. Li < Na < Rb < K < Cs

Answer 1

Answer: (A)

On moving downward in a group, density increases but the density of K is somewhat lesser than Na.
Thus, the order of density is Li < K < Na < Rb < Cs
Densities are
Li - 0.53 g/cc
Na - 0.97 g/cc
K-0.86 g/cc
Rb - 1.53 g/cc
Cs - 1.90 g/cc