d and f BLOCK ELEMENTS

What is the consequence of d-electrons providing less effective shielding than s or p electrons?

• It causes a steeper increase in ionisation enthalpies
• It leads to a more gradual increase in ionisation enthalpies across the transition series
• It makes the atoms larger
• It decreases the nuclear charge

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

• The second electron is always a d-electron
• Removing the second electron involves overcoming the increased effective nuclear charge experienced by the remaining electrons
• The atomic radius increases after the first ionisation
• The second electron is farther from the nucleus

How does the metallic bonding in transition metals differ from that in s-block metals?

• Transition metals have weaker metallic bonds
• Transition metals utilise both ns and (n-1)d electrons for delocalisation, leading to stronger bonds
• S-block metals utilise d-electrons for bonding
• There is no difference in metallic bonding

What is the significance of the d5 configuration in determining ionisation enthalpies?

• It is the least stable configuration
• It represents a particularly stable electron arrangement that can cause breaks in ionisation enthalpy trends
• It is only stable for chromium
• It has no special significance

Why do the 3d transition metals generally have high melting and boiling points?

• Due to weak van der Waals forces
• Due to the strong metallic bonding involving a large number of delocalised electrons from both ns and (n-1)d orbitals
• Due to the formation of covalent networks
• Due to the presence of ionic bonds