Please solve 7 qestion

Dear student. Consider how we might explain the bonding in a compound of divalent beryllium, such as beryllium hydride, BeH 2 . The beryllium atom, with only four electrons, has a configuration of 1 s 2 2 s 2 . Note that the two electrons in the 2 s orbital have opposite spins and constitute a stable pair that has no tendency to interact with unpaired electrons on other atoms ... The only way that we can obtain two unpaired electrons for bonding in beryllium is to promote one of the 2 s electrons to the 2 p level. However, the energy required to produce this excited-state atom would be sufficiently great to discourage bond formation. It is observed that Be does form reasonably stable bonds with other atoms. Moreover, the two bonds in BeH 2 and similar molecules are completely equivalent; this would not be the case if the electrons in the two bonds shared Be orbitals of different types, as in the excited state .. Regards.