Zero Group || First Group (Ag+, Hg2+2, Pb+2)

Zero group was introduced by

Leaving Groups || SN2

Group 2 elements are

Group 2 elements belong to

2nd group Cation (Hg+2, Pb+2, Cu+2, Cd+2, Rn+3)

3rd Group Cation (Al=3, Cr+3, Fe+3) || 4th Group Cation (Mn+2, Zn+2,Ni+2, Co+2) || 5th Group Cation (Ba+2, Cr+2, Ca+2) || 6th Group Cation (Mg+2)