JEE Main 2024ChemistryClassification of Elements and Periodicity in PropertiesEasyMCQ

JEE Main 2024 — Classification of Elements and Periodicity in Properties Question with Solution

JEE Main 2024 (29 Jan Shift 2)

Question

The element having the highest first ionization enthalpy is

Choose an option

Show full solutionCorrect option: C
Correct answer
CN

Step-by-step explanation

The first ionisation energy is the energy needed to remove the outermost, or highest energy, electron from a neutral atom in the gas phase. 

The ionisation energy decreases from top to bottom in groups, and increases from left to right across a period. Nitrogen and carbon belong to second period elements, hence they have more ionisation energy than the other two elements.

It is highest for nitrogen because nitrogen is a more stable half-filled electronic configuration.

Al<Si<C<N; IE1 order.

Hence option C is the answer.

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About this question

This is a previous-year question from JEE Main 2024, covering the Classification of Elements and Periodicity in Properties chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.