A molecule with the formula AX₄Y has all its elements from p-block. Element A is rarest, monoatomic, non-radioactive from its group and has the lowest ionization enthalpy value among A, X and Y. Elements X and Y have first and second highest electronegativity values respectively among all the known elements. The shape of the molecule is:

Shape of AX4Y Molecule | JEE Main PYQ | Chemical Bonding

(A) Pentagonal planar

(B) Square pyramidal

(D) Octahedral

Correct Answer: Square pyramidal

Explanation

Element A corresponds to Xenon (noble gas with lowest ionization enthalpy in group), X is Fluorine and Y is Oxygen.

AX₄Y corresponds to XeOF₄ which has sp³d² electron geometry and square pyramidal molecular shape due to one lone pair.

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JEE Main Chapter-wise PYQs – Chemistry