Question

Find the sum of nodal plane of ${\sigma }_{s-s}^{\ast }$ anti-bonding molecular orbital and ${\sigma }_{s-p}$ bonding molecular orbital.

Answer 1

${\sigma }_{s-s}^{\ast }$ anti-bonding molecular orbital contains 1 nodal plane and ${\sigma }_{s-p}$ bonding molecular orbital contains 0 nodal planes.
Hence, the sum of nodal plane of ${\sigma }_{s-s}^{\ast }$ anti-bonding molecular orbital and ${\sigma }_{s-p}$ bonding molecular orbital is $0+1=1$.