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JEE Main 25 February 2021, Shift 2, Chemistry Q53

Question 53 of 90 in this shift, Chemistry question 23 of 30, Section B.

Electromagnetic radiation of wavelength 663 nm is just sufficient to ionise the atom of metal A. The ionization energy of metal A in kJ mol

^{-1}

is ________. (Rounded-off to the nearest integer) [h

=6.63\times10^{-34}

Js, c

=3.00\times10^{8}

^{-1}

\mathrm{N_A}=6.02\times10^{23}

mol

^{-1}

]

Official answer

181

NTA final key.

Chapter: Structure of Atom
Topic: Bohr's Atomic Theory
Idea tested: Ionization and Excitation Energy

Same idea in other shifts

Asked 6× in all

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Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.