In which of the following pairs, electron gain enthalpies of constituent elements are nearly the same or identical?
(A) $Rb$ and $Cs$
(B) Na and $K$
(C) $Ar$ and $Kr$
(D) $I$ and $At$
Choose the correct answer from the options given below

Question

In which of the following pairs, electron gain enthalpies of constituent elements are nearly the same or identical?

(A) $Rb$ and $Cs$

(B) Na and $K$

(C) $Ar$ and $Kr$

(D) $I$ and $At$

Choose the correct answer from the options given below

TestHub · Accepted Answer

Rb & Cs have nearly same electron gain enthalpy Their values are nearly = - 46 kJ / mol Ar & Kr also have same ΔH e . g . . Value is + 96 kJ / mol . Na and K have different values ( - 53 and - 48 kJ / mol ) . And I and At has values of - 295 and - 270 kJ / mol . As we move down the group value of electron gain enthalpy decreases, with few exceptions.

Chemistry - PERIODIC TABLE Question with Solution | TestHub

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