Question

The colored complexes of the transition elements have color because they:

• A. have very high formation constants
• B. absorb light of some visible wavelengths
• C. absorb light of some ultraviolet wavelengths
• D. have unpaired electrons
• E. are soluble in water

Answer 1

Answer: (B)

absorb light of some visible wavelengths

The colored complexes of the transition elements have color because they absorb light of some visible wavelengths.
Note: Color of transition metal complexes is attributed to the presence of incomplete (n-1) d orbital and number of unpaired electrons. Light in visible region is absorbed which promotes an electron from lower to higher energy level within d orbitals (d-d transition). The colour observed is complimentary to colour absorbed.