Discussion Forum

Which group contains coloured ions out of

1. $Cu^{2+}$     2. $Ti^{4+}$

3. $Co^{2+}$     4. $Fe^{2+}$

Answer:

Explanation:

$Cu^{2+}[Ar]3d^{9}, Ti^{4+}[Ar]3d^{0} Co^{2+}[Ar]3d^{7},Fe^{2+}[Ar]3d^{6}$

1,3,4 are coloured ions hence the answer is b.