Question

Predict whether or not a Mg2 molecule is stable.

Answer 1

Answer:

Option D : Mg2 is not stable

Explanation:

mg has no free valence electrons in its last shell to pair and form bond with other elements. That is why Mg2 is highly unstable.

Answer 2

Answer: d) $Mg_2$ is not stable

Explanation: Magnesium is an element with atomic number of 12, that is there are 12 electrons. So $Mg_2$ has 24 electrons which are arranged as follows according to molecular orbital theory.

$Mg_2:\sigma1s^2\sigma^*1s^2\sigma2s^2\sigma^*2s^2\sigma2p_z^2 \pi2p_x^2=\pi2p_y^2\pi^*2p_x^2=\pi^*2p_y^2\sigma^*2p_z^2\sigma3s^2\sigma^*3s^2$

$\text{bond order} =\frac{\text{no of bonding electrons - no of antibonding electrons}}{2}$

$\text{bond order} =\frac{ 12-12}{2}$

$\text{bond order}=0$

As the bond order is zero, that means there is no bond, thus $Mg_2$ is not stable and do not exist.