Use molecular orbital theory to explain why the $\mathrm{Be}_{2}$ Molecule does not exist.
$Be$ $(\mathrm{Z}=4)$, so electron configuration $1 \mathrm{~s}^{2} 2 \mathrm{~s}^{2}$.
In $\mathrm{Be}, 4$ electrons and in $\mathrm{Be}_{2}$ total eight electrons.
Electron configuration of $\mathrm{Be}_{2}:\left(\sigma_{1 s}\right)^{2}\left(\sigma_{1 s}^{*}\right)^{2}\left(\sigma_{2 s}\right)^{2}\left(\sigma_{2 s}^{*}\right)^{2}$
So, $BMO$ $\left(N_{b}\right)=4$ and ABMO $\left(N_{a}\right)=4$
$BO$ $=\frac{1}{2}\left(\mathrm{~N}_{\mathrm{b}}-\mathrm{N}_{\mathrm{a}}\right)=\frac{1}{2}(4-4)=0$
Bond order of $\mathrm{Be}_{2}$ is zero, so, $\mathrm{Be}_{2}$ is unstable and not possible.
The species having bond order different from that in $\mathrm{CO}$ is
Which of the following molecule is paramagnetic
The linear combination of atomic orbitals to form molecular orbitals takes place only when the combining atomic orbitals
$A$. have the same energy
$B$. have the minimum overlap
$C$. have same symmetry about the molecular axis
$D$. have different symmetry about the molecular axis
Choose the most appropriate from the options given below:
In which of the following pairs the two molecules have identical bond order
What bond order does $O_2^{2 - }$ have