JEE Main 2014ChemistryStructure of AtomMediumMCQ

JEE Main 2014 — Structure of Atom Question with Solution

JEE Main 2014 (19 Apr Online)

Question

The ionization energy of gaseous Na atoms is 495.5 kJ mol-1. The lowest possible frequency of light that ionizes a sodium atom is 

(h=6.626×10-34 Js, NA=6.022×1023 mol-1)

Choose an option

Show full solutionCorrect option: A
Correct answer
A1.24×1015 s-1

Step-by-step explanation

One photon ionises one Na-atom by elastic collision.

NA  hvphoton×10–3 (KJ mole–1)

6·022×1023×6·626×10-34×υphoton×10-3=495·5

υphoton=495·56·022×6·626×10-14

=12.41×1014

=1·241×1015 sec-1

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About this question

This is a previous-year question from JEE Main 2014, covering the Structure of Atom 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.