Question

Which of the following series correctly represents relations between the elements from X to Y?
$X->Y$
A. $_{6}C-{{>}_{32}}Ge$, atomic radii increases
B. $_{3}Li-{{>}_{19}}K$, ionization enthalpy increases
C. $_{9}F-{{>}_{35}}Br$, electron gain enthalpy with negative sign increases
D. $_{18}Ar-{{>}_{54}}Xe$, noble character increases

Answer 1

Hint: Noble character of elements is inversely proportional to the size of the elements. Ionisation potential of the elements is also inversely proportional to the size of the elements. Now the atomic radii of elements increases down the group and decreases along the period. Again electron gain enthalpy is also inversely proportional to the atomic radius of the elements. We need to know about all the periodic trends of a periodic table in detail for solving the question.

Complete step by step answer:
-Ionization potential is defined as the energy required to remove an electron from the valence shell of an atom.
-Electron gain enthalpy is defined as the energy released when an electron is added to the valence shell of an atom.
-Now ionisation potential value decreases down the group as the atom's radius increases down the group so the option B is incorrect.
-Again electron gain enthalpy also decreases down the group as atomic radius increases down the group so the option c is also incorrect.
-Noble character of an atom is also inversely proportional to the size of the atom. Therefore an option d as the size of the noble gases increases down the group their food they are noble character decreases therefore option d is also incorrect.
-Now we know that atomic radii of elements increases down the group therefore option A is correct.

Note: If an electron is added to the valence shell of a small atom then the electron electron repulsion will be more as the space is small. But in case of the large atoms the intramolecular space is quite large. As a result the electron electron repulsion will be less even after adding a valence electron to the valence shell .