d and f BLOCK ELEMENTS

What is the primary reason for the stabilization of certain electron configurations in transition metals?

• Exchange energy
• Kinetic energy
• Potential energy
• Electron affinity

Why is the second ionisation enthalpy of a transition element significantly higher than the first?

• The second electron is always a d-electron
• The second electron is removed from a positively charged ion, experiencing a higher effective nuclear charge
• The atomic radius increases after the first ionisation
• The second electron is in a lower energy level

What is the effect of effective shielding by (n-1)d electrons on the atomic radii of transition elements?

• It causes the atomic radii to increase significantly
• It causes the atomic radii to decrease only slightly across the transition series
• It has no effect on atomic radii
• It causes fluctuations in atomic radii

Why do transition metals generally have high melting and boiling points?

• Weak van der Waals forces
• Strong metallic bonding involving delocalised d-electrons results in strong interatomic forces
• They form covalent network structures
• They have low atomic masses

What is the significance of the d5 electron configuration in transition metal chemistry?

• It is the most unstable configuration
• It represents a particularly stable arrangement that influences ionisation energies and compound stability
• It is only found in chromium
• It has no special significance