Match the LIST-I with LIST-II
(According to Bohr model of hydrogen atom)
| LIST-I (Energy levels in a hydrogen atom) | LIST-II (Principal quantum number) | ||
| A. | \( -1.51\,\mathrm{eV} \) | I. | \( n=2 \) |
| B. | \( -0.85\,\mathrm{eV} \) | II. | \( n=\infty \) |
| C. | \( -3.4\,\mathrm{eV} \) | III. | \( n=4 \) |
| D. | \( 0\,\mathrm{eV} \) | IV. | \( n=3 \) |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A-IV, B-III, C-I, D-II
In the Bohr model the energy of the electron in the n-th orbit of hydrogen is
\( \displaystyle E_n = -\frac{13.6}{n^{2}}\,\mathrm{eV} \)
(A) \( -1.51\,\mathrm{eV} \) — this matches (IV) \( n=3 \). \( -13.6/9 = -1.51\,\mathrm{eV} \).
(B) \( -0.85\,\mathrm{eV} \) — this matches (III) \( n=4 \). \( -13.6/16 = -0.85\,\mathrm{eV} \).
(C) \( -3.4\,\mathrm{eV} \) — this matches (I) \( n=2 \). \( -13.6/4 = -3.4\,\mathrm{eV} \).
(D) \( 0\,\mathrm{eV} \) — this matches (II) \( n=\infty \). As \( n\to\infty \), \( E_n\to 0 \): the electron is just free (the atom is ionised).
NCERT (2026-27):
Energy Levels – “… From Eq. (12.10), for n = 2; the energy E2 is –3.40 eV.”
Energy Levels – “… Similarly, E3 = –1.51 eV and E3 – E1 = 12.09 eV, or to excite the hydrogen atom from its ground state (n = 1) to second excited state (n = 3), 12.09 eV energy is required, and so on.”
Energy Levels – “… In this diagram, the highest energy state corresponds to n =∞ in Eq, (12.10) and has an energy of 0 eV.”