d and f BLOCK ELEMENTS

What is the electronic configuration of the Ni+ ion?

• [Ar] 3d8
• [Ar] 3d7 4s2
• [Ar] 3d8 4s1
• [Ar] 3d9

Based on Table 4.2, which element has the lowest third ionization enthalpy (ΔiH° III) among Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn?

• Titanium (Ti)
• Vanadium (V)
• Scandium (Sc)
• Chromium (Cr)

What is the electronic configuration of the Cr+ ion?

• [Ar] 3d4 4s1
• [Ar] 3d5 4s1
• [Ar] 3d5
• [Ar] 3d3 4s2

Why does the imperfect shielding effect become more pronounced for 4f electrons compared to d electrons?

• 4f electrons are held closer to the nucleus
• 4f electrons repel each other more strongly
• 4f orbitals are more diffuse and less effective at screening the nuclear charge
• d electrons are removed first

According to Table 4.2, what is the approximate first ionization enthalpy (ΔiH° I) of Scandium (Sc)?

• 656 kJ mol–1
• 650 kJ mol–1
• 631 kJ mol–1
• 717 kJ mol–1