Question

why the density of Na is grater than K​

Answer 1

Hello Friend..

The answer if your question is-

Actually in case sodium and potassium the increase in the shell size outweights the pull of the core on the outer shell electron and so potassium is less dense than sodium...

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Answer 2

$\fcolorbox{red}{green}{Hey Mate Here Is Your Answer}$

$\textit{Density Of Na Is Greater Than K Because}$

There is an abnormal increase in atomic size and atomic volume as we move from sodium to potassium And when we move from Na to K effect of increase in volume is more pronounced as compared to effect of increase in atomic mass. Due to this potassium is less dense than sodium.

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