Question

In monomeric $B{H}_3$, let an axis definition place the molecule in the xz plane. Which atomic orbital on $B$ is non-bonding?

• A. $2s$
• B. $2p_x$
• C. $2p_y$
• D. $2p_z$

Answer 1

The correct option is C $2p_y$

When the molecule is in xz plane, the atomic orbitals which are in the xz plane will take part in bonding. These orbitals include 2s, $2p_x$ and $2p_z$ orbitals.
$2p_y$ orbital is perpendicular to the xz plane. It will remain non bonding.