Question

The order of ionisation energies of the coinage metals is:

• A. $Cu>Ag<Au$
• B. $Cu>Ag>Au$
• C. $Cu<Ag<Au$
• D. $Au>Ag<Cu$

Answer 1

The correct option is A $Cu>Ag<Au$

As we move from the first to the second transition series, ionization energy decreases due to the increase in the number of shells. However, as we move from the second to the third transition series, due to the poor shielding of f electrons, ionization energy increases. Thus the ionisation energies of the coinage metals follow the order $Cu>Ag<Au$.