d and f BLOCK ELEMENTS

Based on the information, how would you expect the reactivity of a metal with a very high enthalpy of atomisation to compare to one with a low enthalpy of atomisation?

• The metal with high enthalpy of atomisation would be more reactive
• The metal with high enthalpy of atomisation would be less reactive
• Their reactivities would be the same
• It is impossible to predict

What is the implication of poor d electron shielding on the effective nuclear charge across a transition series?

• Effective nuclear charge decreases
• Effective nuclear charge remains constant
• Effective nuclear charge increases
• Effective nuclear charge fluctuates randomly

Why are the atomic radii of 5d series elements nearly the same as 4d series elements, despite having an additional electron shell?

• Because 5d electrons shield more effectively
• Due to the Lanthanoid contraction compensating for the size increase
• Because the nuclear charge decreases
• Because 5d electrons are held less tightly

What is the expected trend in atomic radii from the 4d series to the 5d series *without* considering the Lanthanoid contraction?

• Decrease
• Remain constant
• Increase
• Fluctuate randomly

Which electrons are primarily responsible for the Lanthanoid contraction?

• 5d electrons
• 4f electrons
• 6s electrons
• 5p electrons