Question

The total number of electrons on the central metal atom / ion including those gained by bonding is called _____.

Answer 1

The total number of electrons on the central metal atom / ion including those gained by bonding is called effective atomic number (EAN).

Example: $\left[Co\right(N{H}_3{)}_6{]}^{3+}$ has $EAN=36$.

In which $24$ is from electrons of $C{o}^{3+}$ and each ammonia molecule gives a lone pair having ${}^{\prime }{2}^{\prime }$ electrons. So $6\times 2=12$

$24+12=36$ which is EAN of $\left[Co\right(N{H}_3{)}_6{]}^{3+}$