JEE MAIN - Chemistry (2011 - No. 10)
Outer electronic configuration of Gd (Atomic no : 64) is -
4f85d06s2
4f45d46s2
4f75d16s2
4f35d56s2
Explicação
Electronic configuration of Gd(64) : [Xe]4f75s25p65d16s2
So the outer electronic configuration will be : 4f75d16s2
Shortcut Method : Gd belongs to 4f series which is also called lanthanide series. In this lanthanide series for Cerium (Ce), Gadolinium (Gd) and Lutetium (Lu) outer d orbital has 1 electron and for all other lanthanide series elements outer d orbital has 0 electron. From this you can easily say option (C) is correct.
So the outer electronic configuration will be : 4f75d16s2
Shortcut Method : Gd belongs to 4f series which is also called lanthanide series. In this lanthanide series for Cerium (Ce), Gadolinium (Gd) and Lutetium (Lu) outer d orbital has 1 electron and for all other lanthanide series elements outer d orbital has 0 electron. From this you can easily say option (C) is correct.