Transition and InnerTransition Elements - Result Question 109

####7. The lanthanide ion that would show colour is

(2019 Main, 8 April I)

(a) Gd3+

(b) Sm3+

(c) La3+

(d) Lu3+

Show Answer

Solution:

  1. The lanthanide ion that would show colour is Sm3+. Colour of a compound depends on the number of electrons in 4f-orbitals. Electronic configuration of given lanthanides are as follows:

Gd3+=4f7 Sm3+=4f5 La3+=4f0 Lu3+=4f14

Gd3+ have half-filled 4f-orbitals.

La3+ have no electron in 4f-orbitals.

Lu3+ have fully-filled 4f-orbitals.

Only Sm3+ contain 4f5. The electrons can easily undergoes excitation. That result in a formation of colour.



जेईई के लिए मॉक टेस्ट

एनसीईआरटी अध्याय वीडियो समाधान

दोहरा फलक