JEE Main 2026 · ChemistryNumerical answerNumerical valueEasyCalculation

JEE Main 2 April 2026, Shift 2, Chemistry Q71

Question 71 of 75 in this shift, Chemistry question 21 of 25, Section B.

The surface of sodium metal is irradiated with radiation of wavelength

x

nm. The kinetic energy of ejected electrons is

2.8 \times 10^{-20}

J. The work function of sodium is 2.3 eV. The value of

x

is (Given:

h = 6.6 \times 10^{-34}

J s;

1

= 1.6 \times 10^{-19}

c = 3.0 \times 10^8

m s

^{-1}

)

Official answer

NTA final key.

Chapter: Structure of Atom
Topic: Bohr's Atomic Theory
Idea tested: Photoelectric Effect Coupling

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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 42 of the 174 JEE Main shifts held from 2017 to 2026.