JEE Main 12 Jan 2019 Evening Question 29
Question: The correct order of atomic radii is
[JEE Main Online Paper Held On 12-Jan-2019 Evening]
Options:
A) $ Ce>Eu>Ho>N $
B) $ Ho>N>Eu>Ce $
C) $ Eu>Ce>Ho>N $
D) $ N>Ce>Eu>Ho $
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Answer:
Correct Answer: C
Solution:
- Given elements are:$ Ce, Eu, Ho, N$
We have to find the correct order of atomic radii.
Cerium $(Ce)$, europium $(Eu)$ and Holmium $(Ho)$ are lanthanide elements.
Their metallic radius is: $Ce$ = 181.8 pm $Eu$ = 208.4 pm $Ho$ = 176.2 pm
Atomic radius of nitrogen $(N)$ = 65 pm.
Thus, the atomic radii follow the order:Eu > Ce > Ho > N.
Hence, the correct option is $(C)$.
