Chemistry, asked by swiftshreyarocks, 11 months ago

(U UU
NI
14. Which of the following trivalent
lanthanide ions is not coloured?
*(a) Er3+
(b) Yb3+ Sofeu
(d) Sm3+
3+
стои право
not colourat- no
(c) Pm3+​

Answers

Answered by kailashmeena123rm
0

Answer:

check electronic configuration

if electrons are paired then no transition and no colour

if electeons are not laired then it shows colour

Answered by rishkrith123
0

Complete question:

Which of the following trivalent lanthanoid ions is not coloured?

(a) Lu⁺³

(b) Pm⁺³

(c) Sm⁺³

(d) Eu⁺³

Answer:

Lu⁺³ ion has no colour.

Explanation:

(a) Electronic configuration of Lutetium (Lu) (Z = 71): [Xe]4f¹⁴ 5d¹ 6s²

Electronic configurationof Lu⁺³ (Z = 68): [Xe] 4f¹⁴

As it has completely filled sub-shell (f) it is hard to excite the electron present in the Lu⁺³ ion.

Therefore, the ion Lu⁺³ does not show any colour.

(b) Electronic configuration of Promethium (Pm) (Z = 61): [Xe]4f⁵ 6s²

Electronic configurationof Pm⁺³ (Z = 58): [Xe] 4f⁴

As it has incomplete filled sub-shell (f) it is easy to excite the electron present in the Pm⁺³ ion.

Therefore, the ion Pm⁺³ shows pink colour.

(c) Electronic configuration of Samarium (Sm) (Z = 62): [Xe]4f⁶ 6s²

Electronic configurationof Sm⁺³ (Z = 59): [Xe] 4f⁵

As it has incomplete filled sub-shell (f) it is easy to excite the electron present in the Sm⁺³ ion.

Therefore, the ion Sm⁺³ shows yellow colour.

(d) Electronic configuration of Euporium (Eu) (Z = 63): [Xe]4f⁷ 6s²

Electronic configurationof Eu⁺³ (Z = 68): [Xe] 4f⁶

As it has incomplete filled sub-shell (f) it is a bit easy to excite the electron present in the Eu⁺³ ion.

Therefore, the ion Eu⁺³ shows pink colour.

Hence, Lu⁺³ ion is colourless.

#SPJ2

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