Question

Which of the following sequence regarding ionisation potential of coinage metal is correct?

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

Answer 1

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

The ionisation energy of the elements is expected to decrease down the group with an increase of distance between the valence electron and the nucleus and as well as because of the decrease in the effective nuclear charge.

So, the amount of energy required to ionize electron will be least for gold (atomic radius max). therefore the sequence regarding ionisation potential of coinage metal is:

$Cu$ $>$ $Ag$ $>$ $Au$

Hence, the correct option is $\text{A}$