<p>Why is&nbsp;<span class="equation">\(E^0(Cu^{2+}|Cu)\)</span>&nbsp;exceptionally positive? Although&nbsp;<span class="equation">\(Cu^{+}\)</span>&nbsp;ion has <span class="equation">\(3d^{10}\)</span>&nbsp;configuration, yet it is unstable in an aqueous solution. Why? What is the reason for the stability of&nbsp; <span class="equation">\(Cu^{2+}\)</span>&nbsp;over&nbsp;<span class="equation">\(Cu^{+}\)</span>&nbsp;ion?​​​​​​​</p>