Question

The colour of ${}_{62}S{m}^{3+}$ is yellow. What is the colour of ${}_{66}D{y}^{3+}$?

• A. Colourless
• B. Yellow
• C. Red
• D. Blue

Answer 1

Answer: (B)

Yellow

Colour of ions depends upon no of unpair electrons for transition. Electronic configuration of ${}_{62}S{m}^{3+},\left[Xe\right]4f^5$ and ${}_{66}D{y}^{3+},\left[Xe\right]4f^9$; they both have same no of electron for transition (5) . There fore they show same colour yellow.