List of top Chemistry Questions on Electronic Configurations Of Elements And The Periodic Table asked in WBJEE

Which of the following ion/ions is/are diamagnetic?
The number of unpaired electrons in $Mn^{2+}$ ion is
The correct pair of electron affinity order is:
Among the following groupings, which one represents the set of iso-electronic species?
The orbital angular momentum of an electron in $ 2s $ -orbital is
The actinoids exhibit more number of oxidation states in general than the lanthanoids because
Atoms in a P4 molecule of white phosphorus are arranged regularly in the following way : 
In the titration of Fe2+ ions versus Cr2O72– ions using diphenylamine as the internal indicator, phosphoric acid is added in the solution containing Fe2+ ions. The role of phosphoric acid is to