The electronic configuration of Cr³⁺ is :

• [Ar] 3d⁴ 4s²

• [Ar] 3d³ 4s⁰

• [Ar] 3d² 4s¹

• [Ar] 3d⁵ 4s¹

The lanthanide contraction is responsible for the fact that :

• Zr and Zn have the same oxidation state

• Zr arid Hf have about the same radius

• Zr and Nb have similar oxidation state

• Zr and Y have about the same radius

Which of the following forms a colourless solution in aqueous medium ?

• Cr³⁺

• V³⁺

• Sc³⁺

• Ti³⁺

The atomic number of Ni and Cu are 28 and 29 respectively .The electronic configuration 1s , 2s² 2p⁶ , 3s² 3p⁶ 3d¹⁰ represents :

• Cu⁺

• Cu²⁺

• Ni²⁺

• Ni

655.

Assertion : Transition metals are poor reducing agents.

Reason : Transition metals form numerous alloys
with other metals.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : The degree of complex formation in actinides decreases in the order ${\mathrm{M}}^{4+} > {\mathrm{MO}}_2^{2+} > {\mathrm{M}}^{3+} > {\mathrm{MO}}_2^{+}$.

Reason : Actinides form complexes with p-bonding ligands such as alkyl phosphines and thioethers.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

The highest magnetic moment is shown by the transition metal ion with the configuration :

• 3d²

• 3d⁵

• 3d⁷

• 3d⁹

A transition metal ion exists in its highest oxidation state .It is expected to behave as :

• a chelating agent

• a central metal in a coordination compound

• an oxidising agent

• a reducing agent

The flame colours of metal ions are due to

• Frenkel defect

• Schottky defect

• metal deficiency defect

• metal excess defect.

Which radioactive element is being used in cancer therapy ?

• ${}_{27}{}^{60}\mathrm{Co}$

• ${}_{28}{}^{62}\mathrm{Ni}$

• ${}_{56}{}^{140}\mathrm{Ba}$

• ${}_{15}{}^{32}\mathrm{P}$