BITSAT 2018 Slot 2 Solved Paper

Protoactinium (Pa) is the element that does not have stable electronic configuration.
Protoactinium (Pa)=[Rn]5f26d17s2( Atomic number =91)
Nobelium (No)=[Rn]5f146d07s2( Atomic number =102)
Lawrencium (Lr)=[Rn]5f146d17s2 (Atomic number =103 )
Amercium (Am)=[Rn]5f76d07s2 (Atomic number =95 )