The catalytic activity of the transition metals and their compounds is ascribed to their
Chemical reactivity
Magnetic behaviour
Unfilled $d-$ orbitals
Ability to adopt multiple oxidation states and their complexing ability
The oxoanion in which the oxidation state of the central atom is same as its group number in the periodic table is
White silver surface turns black when $O_3$ is passed over it. This is due to the formation of
Four successive members of the first row transition elements are listed below with their atomic numbers. Which one of them is expected to have the highest third ionization enthalpy
The element exhibiting most stable $ + \,2$ oxidation state among the following is
Assertion : Cuprous ion $(Cu^+)$ has unpaired electrons while cupric ion $(Cu^{2+})$ does not.
Reason : Cuprous ion $(Cu^+)$ is colourless whereas cupric ion $(Cu^{2+})$ is blue in the aqueous solution.