Question

what is the reason of coloured ion in transition metal​

Answer 1

Answer:

The reason why transition metal in particular are colorful is because they have unfilled or either half filled d orbitals. There is Crystal field theory which explains the splitting of the d orbital, which splits the d orbital to a higher and lower orbital. Now, the electrons of the transition metal can "jump"

Answer 2

Explanation:

The reason why transition metal in particular are colorful is because they have unfilled or either half filled d orbitals. There is Crystal field theory which explains the splitting of the d orbital, which splits the d orbital to a higher and lower orbital. Now, the electrons of the transition metal can "jump".