IEMJEE Chemistry preparation: Hydrogen-like energy levels — practice worksheet with answers

How to use this worksheet

This independent worksheet checks hydrogen-like energy levels with a new problem, an explanation task and an interleaved related skill. It is not an official IEM question paper, a difficulty forecast or a prescribed timed examination.

Write an attempt first, then compare your method with the visible answers. Record whether a miss came from interpretation, a missing concept, execution or a condition you overlooked.

Question 1: apply the topic

What is the ionisation energy from that level in the model?

Answer and checking point

3.4 eV is needed to reach the zero-energy limit.

Check atom and charge bookkeeping, units, signs and the identity of the species to which a statement applies. For an organic transformation, retain the substrate and conditions. A familiar reagent or periodic trend is not enough to prove every proposed product or comparison.

Question 2: diagnose an approach

Explain why the following warning matters and identify the correction it calls for: An energy level's negative sign reflects its chosen bound-state zero; it does not mean emitted photon energy is negative.

Model checkpoint: The simple Bohr energy formula applies to one-electron hydrogen-like species, not general many-electron atoms. Governing rule: Eₙ=−13.6 Z²/n² eV in the ideal model.

Question 3: transfer to nucleophilic substitution basics

Does the same label hydroxide guarantee substitution rather than elimination under every condition?

Answer: No. Conditions and substrate can favour elimination.

This is an interleaved related-skill task, not a claim that the two topics have identical methods. Explain which idea changes when switching from the main topic to this one.

Review the attempt

Separate correct answers reached with a justified method from lucky guesses. Rework missed steps without looking at the answer, then use a fresh problem from an appropriate primary textbook or official paper. Do not use a small worksheet result as an admission cutoff, rank or readiness guarantee.

Official sources and verification

Sources checked on 26 October 2026. A source’s date, programme and campus limit which claims it supports. Official pages may change after review.

1. UEM — IEMJEE examination information

   Historical examination pattern; verify the current cycle on the central portal.

2. NTA — explicitly labelled JEE Main 2026 syllabus

   Historical PCM syllabus reference. Lessons and exercises are independently authored, not official IEMJEE papers or verified 2027 paper predictions.

3. NCERT — official textbook catalogue

   Primary textbook reference for checking school-level concepts. This directory does not certify the independent lesson or establish IEM examination weightage.

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