d and f BLOCK ELEMENTS

Why is the third ionization enthalpy of Zn relatively low?

• Ionization leads to the formation of a stable d10 configuration
• Ionization disrupts a stable d10 configuration
• Ionization leads to the formation of a stable d5 configuration
• Ionization disrupts a stable d5 configuration

Why do Cr and Cu exhibit unusually high second ionization enthalpies?

• Their M+ ions achieve stable d5 and d10 configurations respectively
• Their M+ ions achieve unstable d4 and d9 configurations respectively
• They have very high atomic radii
• They have very low nuclear charges

Why is the ionization enthalpy of Fe2+ lower than that of Mn2+?

• Fe2+ has a d6 configuration which gains stability from losing an electron, unlike the stable d5 configuration of Mn2+
• Mn2+ has a d5 configuration which gains stability from losing an electron, unlike the stable d6 configuration of Fe2+
• Fe2+ has a smaller ionic radius
• Mn2+ has a larger ionic radius

Why is the ionization enthalpy of Mn+ lower than that of Cr+?

• Mn+ has a less stable 3d54s1 configuration compared to Cr+'s d5 configuration
• Cr+ has a less stable d5 configuration compared to Mn+'s 3d54s1 configuration
• Mn+ has a higher nuclear charge
• Cr+ has a lower effective nuclear charge

According to Hund's rule, what is the preferred arrangement of electrons in degenerate orbitals for the lowest energy state?

• Maximum single occupation with parallel spins
• Maximum single occupation with opposite spins
• Minimum single occupation with parallel spins
• Complete pairing in the first few orbitals