Question

Which element contains a non-spherical electron density?

• A. $He$
• B. $B$
• C. $Be$
• D. $Li$

Answer 1

The correct option is B $B$

$s$-orbital is spherical in shape so the electrons present in $s$-orbital will have spherical eletron density.
Option(a)
Electronic configuration of $He$ : $1s^2$ (spherical eletron density)
Option(b)
Electronic configuration of $B$ : $1s^{2}2s^{2}2p^1$
B has electron in $p$-orbital so it can contain non-spherical electron density as well.
Option(c)
Electronic configuration of $Be$ : $1s^{2}2s^2$ (spherical electron density)
Option(d)
Electronic configuration of $Li$ : $1s^{2}2s^1$ (spherical electron density)
Hence, the correct option is (b).