The Bohr model for the spectra of a H-atom
A. Will not be applicable to hydrogen in the molecular form
B. Will not be applicable as it is for a He-atom
C. Is valid only at room temperature
D. Predicts continuous as well as discrete spectral lines
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A, B only
The Bohr model treats a single electron moving round a nucleus in stationary orbits with quantised angular momentum. It gives discrete energy levels for hydrogen-like (one-electron) atoms.
(A) Will not be applicable to hydrogen in the molecular form — Correct. A hydrogen molecule has two nuclei and two electrons; the model describes only one electron round one nucleus.
(B) Will not be applicable as it is for a He-atom — Correct. Helium has two electrons, and the repulsion between them is not included in the model; it applies only to one-electron ions such as \( \mathrm{He^{+}} \).
(C) Is valid only at room temperature — Incorrect. The postulates contain no condition on temperature.
(D) Predicts continuous as well as discrete spectral lines — Incorrect. Transitions between fixed energy levels give only discrete lines; the model does not predict a continuous spectrum.
NCERT Exemplar:
Atoms – …
