Question

Which of the following noble gases is the most reactive and forms the maximum number of compounds?

• A. Helium
• B. Neon
• C. Argon
• D. Xenon

Hint:

Reactivity in noble gases directly correlates inversely with ionization energy. The larger the atom (like Kr and Xe), the more easily it can be forced to share its electrons with highly electronegative atoms like F and O.

Answer 1

The Correct Option is D

Step 1: Understanding the Question:
The question asks to identify the noble gas that exhibits the highest chemical reactivity and forms the most extensive array of chemical compounds among the given options.

Step 3: Detailed Explanation:
Noble gases (Group 18 elements) are generally unreactive due to their stable, completely filled valence electron configurations (\(ns^2 np^6\), except He which is \(1s^2\)).
However, as we move down the group from Helium to Radon, the atomic radius increases and the ionization enthalpy decreases significantly.
Among the stable noble gases provided in the options,

Xenon (Xe) has the largest atomic size and the lowest ionization enthalpy.
Its first ionization energy (\(1170\text{ kJ/mol}\)) is remarkably close to that of molecular oxygen (\(1175\text{ kJ/mol}\)). This similarity allowed Neil Bartlett to successfully synthesize the first noble gas compound, \(\text{XePtF}_6\).
Because its outermost electrons are less tightly held by the nucleus, Xenon can easily share or donate electrons to highly electronegative elements like Fluorine and Oxygen, forming numerous stable compounds (e.g., \(\text{XeF}_2, \text{XeF}_4, \text{XeF}_6, \text{XeO}_3, \text{XeOF}_4\)).

Step 4: Final Answer:
The correct choice is (D).