6 Because of small size and high electronegativity oxygen or fluorine can
oxidise the metal to its highest oxidation state 4 7 Cr
2+ is stronger reducing agent than Fe
2+
Reason: d
4   d
3 occurs in case of Cr
2+ to Cr
3+
But d
6   d
5 occurs in case of Fe
2+ to Fe
3+
In a medium (like water) d
3 is more stable as compared to d
5 (see CFSE)
4 9 Cu
2Cu+ in aqueous solution underoes disproportionation, i