d and f BLOCK ELEMENTS

Which orbital filling sequence is responsible for the Lanthanoid contraction?

• 5d orbitals filled before 4f orbitals
• 4f orbitals filled before 5d orbitals
• 3d orbitals filled before 4f orbitals
• 4p orbitals filled before 4f orbitals

What is a consequence of the higher enthalpies of atomisation observed in the second and third series of transition metals?

• Lower melting points
• Less stable compounds
• More frequent metal-metal bonding in compounds
• Decreased density

Which of the following best describes the shielding effect of a d electron?

• Very effective
• Moderately effective
• Not very effective
• It depends on the specific d orbital

What is the relationship between the enthalpy of atomisation and the standard electrode potential of a metal, according to the text?

• They are always directly proportional
• They are always inversely proportional
• Enthalpy of atomisation is an important factor in determining the standard electrode potential
• There is no relationship

Compared to the first (3d) series, how do the atomic radii of the second (4d) series of transition metals generally change?

• Remain the same
• Decrease
• Increase
• Fluctuate randomly