D-And F-Block Elements Ques 421
Question: The aqueous solution containing which one of the following ions will be colourless
[CBSE PMT 2000, 05]
Options:
A) $ S{{c}^{3+}} $
B) $ F{{e}^{2+}} $
C) $ T{{i}^{3+}} $
D) $ M{{n}^{2+}} $ (Atomic number Sc = 21, Fe = 26, Ti = 22, Mn = 25)
Show Answer
Answer:
Correct Answer: A
Solution:
$ _{21}Sc\to 1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{1} $
$ S{{c}^{+3}}\to 1s^{2}2s^{2}2p^{6}3s^{2}3p^{6} $ Due to presence of paired electron it will be colourless.
