Question

Which of the following elements in +3 oxidation state forms colourless compounds?

• A. \(\text{Sc}\)
• B. \(\text{Ni}\)
• C. \(\text{Cr}\)
• D. \(\text{V}\)

Hint:

Colour comes from d-d transitions, which need partly filled d orbitals; Sc3+ has d0.

Answer 1

The Correct Option is A

Step 1: Find d count
Sc3+ 0, V3+ 2, Cr3+ 3, Ni3+ 7.

Step 2: Colour rule
No d electrons means no d-d transition and no colour.

Step 3: Answer
Option (A).

Final Answer:
Option (A). \[ \boxed{\text{Sc}} \]