Atomic Structure: JEE Main Chemistry Question with Solution
The number of following statement/s which is/are incorrect is
(A) Line emission spectra are used to study the electronic structure
(B) The emission spectra of atoms in the gas phase show a continuous spread of wavelength from red to violet
(C) An absorption spectrum is like the photographic negative of an emission spectrum
(D) The element helium was discovered in the sun by spectroscopic method
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Hint 1 of 2
Which statement among the given options regarding atomic spectra is incorrect?
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Step-by-step solutionView
Correct answer
Only statement (B) is incorrect, so the total number of incorrect statements is 1.
Option analysis
Why each option works or fails
Reviewed route
Solution
StepWorking
01given
Four statements regarding atomic spectra:
(A) Line emission spectra are used to study the electronic structure.
(B) The emission spectra of atoms in the gas phase show a continuous spread of wavelength from red to violet.
(C) An absorption spectrum is like the photographic negative of an emission spectrum.
(D) The element helium was discovered in the sun by spectroscopic method.
02strategise
Evaluate the correctness of each statement individually according to standard atomic theory and NCERT facts, then count the total number of incorrect statements.
03execute
Evaluating statement-by-statement:
- (A) Correct: Line emission spectra give characteristic discrete lines corresponding to electronic transitions. These lines are used to determine electronic structures.
- (B) Incorrect: Emission spectra of atoms in the gas phase do NOT show a continuous spread of wavelengths. They emit light only at specific discrete wavelengths with dark spaces between them (line spectra).
- (C) Correct: An absorption spectrum consists of dark lines where radiation is absorbed. These correspond directly to the bright lines in an emission spectrum. This makes it analogous to a photographic negative.
- (D) Correct: Helium (from Greek 'helios' meaning Sun) was indeed first discovered in the solar spectrum using spectroscopic methods.
Total number of incorrect statements = 1 (only statement B).
✓verify
Re-verified: Only (B) is incorrect since atomic spectra are discrete/discontinuous line spectra, not continuous. Statements A, C, and D are direct factual statements from NCERT Chemistry (Atomic Structure). Total incorrect = 1.
✓ Source and academic review↓
Question type
Numerical
Exam relevance
JEE Main · Chemistry
Concepts assessed
Chemistry
Academic status
Reviewed by official_key
Source
pyq
Editorial review
3 September 2026
Quick checks
Students also ask
Why is the emission spectrum of atoms in the gas phase not continuous?
Gaseous atoms have quantized electronic energy levels. Transitions between these levels emit photons of very specific, discrete frequencies/wavelengths rather than a continuous continuum.