# According to molecular orbital theory,

Question:

According to molecular orbital theory, the species among the following that does not exist is:

1. $\mathrm{He}_{2}^{-}$

2. $\mathrm{He}_{22}^{+}$

3. $\mathrm{O}_{2}^{2-}$

4. $\mathrm{Be}_{2}$

Correct Option: , 4

Solution:

B. O. of $B e_{2}$ is zero, So it does not exist.