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

Options

A. Hydration energy `Li^(+)gtNa^(+)gtK^(+)gtRb^(+)`
B. Ionisitation energy: `LigtNagtKgtRB`
C. Density `Li lt Na lt K lt Rb`
D. Atomic size` Lilt Na lt K lt Rb`

Answer

C

Explanation

In general on moving downward in group, density increases 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(86pm) to K (227pm).