For alkali metals, which one of the following trends is incorrect ?

Options

A. Hydration energy-`LigtNagtKgtRb`
B. Ionisation energy-`LigtNagtKgtRb`
C. Density-`LiltKltNaltRb`
D. Atomic size -`LiltNaltKltRb`

Answer

C

Explanation

In genral ,density increases on moving downward in a group but density of potassium (K) is lesser than that of the sodium (Na).This is because of the abnormal increase in atomic size on moving from Na (86 pm) to K (227pm).Thus,the correct order of density is
`LiltKltNalt RB`