What is effective atomic number (EAN) ?
Calculate EAN of cobalt (Z=27) in `[CO(NH_(3))_(6)]^(+3)` and of zinc (z=30) in `[Zn(NH_(3))_(4)]SO_(4)`.

Explanation

Effective Atomic Number (EAN) : EAN represents the total number of electrons surrounding the nucleus of a metal atom in a metal complex. It is composed of the metal atom's electrons and the bonding electron from the surrounding electron donating atom and molecules.
CAlculation of EAN :
`[Co(NH_(3))_(6)]^(+3)" "Co^(3+)` electrons = 24
Each `NH_(3)` contributes 2 bonding electrons. thus 6 `NH_(3)` contributes `6xx2=12` bonding electrons.
Thus, EAN of cobalt in `[CO(NH_(3))_(6)]^(3+)` is
24+12=36
`[Zn(NH_(3))_(4)]SO_(4)" "Zn^(2+)` electrons = 28
Each `NH_(3)` contributes 2 bonding elctrons. Thus 4
`NH_(3)` contributes `4xx2=8` bonding elctrons.
Thus, EAN of Zn in `[Zn(NH_(3))_(4)]SO_(4)` is 28 + 8 = 36