Learn

Saturday, 31 October

JEE Main 2023 · ChemistryNumerical answerNumerical valueMediumCalculation

JEE Main 10 April 2023, Shift 2, Chemistry Q81

Question 81 of 90 in this shift, Chemistry question 21 of 30, Section B.

The electron in the nthn^{th} orbit of Li2+\mathrm{Li^{2+}} is excited to (n+1)(n + 1) orbit using the radiation of energy 1.47×10−171.47 \times 10^{-17} J (as shown in the diagram). The value of n is ________. Given: RH=2.18×10−18R_H = 2.18 \times 10^{-18} J

The figure, in words

Energy-level diagram: upper horizontal line labelled n+1, lower horizontal line labelled n; vertical upward arrow between them (excitation); wavy arrow from upper to lower level labelled 1.47×10−171.47\times10^{-17} J.

Official answer

1

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
  1. 2 Apr 2026, Shift 1 · Q52What is the energy (in J atom−1\mathrm{J\ atom^{-1}}) required for the following process ? Li2+(g)→Li3+(g)+e−\mathrm{Li^{2+}(g)\rightarrow Li^{3+}(g)+e^-} (Take…EasySingle correct
  2. 31 Jan 2024, Shift 1 · Q82The ionization energy of sodium in kJ mol−1^{-1}, if electromagnetic radiation of wavelength 242 nm is just sufficient to ionize sodium…MediumNumerical value
  3. 28 Jul 2022, Shift 2 · Q53If the wavelength for an electron emitted from H-atom is 3.3×10−103.3\times10^{-10} m, then energy absorbed by the electron in its ground state…MediumNumerical value
  4. 25 Jun 2022, Shift 1 · Q83The longest wavelength of light that can be used for the ionisation of lithium atom (Li) in its ground state is x×10−8x \times 10^{-8} m. The…MediumNumerical value
  5. 25 Feb 2021, Shift 2 · Q53Electromagnetic radiation of wavelength 663 nm is just sufficient to ionise the atom of metal A. The ionization energy of metal A in kJ…MediumNumerical value

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. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.