JEE Main - Spectrum of hydrogen atom and Bohr model basics One Line Questions & Answers

1. The energy of an electron in the nth orbit of a hydrogen atom is given by E_n = -13.6/n² eV. What is the energy of the electron in the ground state (n=1)? — -13.6 eV

2. The energy of the second excited state (n=3) of a hydrogen atom is: — -1.51 eV

3. What is the radius of the first Bohr orbit (n=1) for the hydrogen atom? — 0.529 Å

4. The kinetic energy of an electron in the nth Bohr orbit of hydrogen is proportional to: — 1/n²

5. The potential energy of an electron in the nth Bohr orbit of hydrogen is proportional to: — 1/n²

6. In the Bohr model, the total energy of an electron in the nth orbit is the sum of its kinetic and potential energies. This total energy is proportional to: — 1/n²

7. What is the value of the Rydberg constant (R_H) in cm⁻¹? — 109737 cm⁻¹

8. What is the ionization energy of a hydrogen atom in its ground state, according to the Bohr model? — 13.6 eV

9. The energy required to excite a hydrogen atom from n=1 to n=3 is: — 12.09 eV

10. If an electron absorbs energy and moves from n=1 to n=3, what is the energy of the absorbed photon? — 12.09 eV

11. The radius of the second Bohr orbit (n=2) is how many times the radius of the first Bohr orbit (n=1)? — 4 times

12. The Bohr radius (a_0) is approximately: — 5.29 x 10⁻¹¹ m

13. The transition of an electron from a higher energy level (n_i) to a lower energy level (n_f) results in: — Emission of a photon

14. What is the relationship between the energy of a photon and its frequency (ν)? — E = hν

15. The energy of the emitted photon when an electron transitions from n_i to n_f is given by: — E = hν = R_H (1/n_f² - 1/n_i²)

16. Which phenomenon is explained by the Bohr model and leads to the characteristic spectral lines of hydrogen? — Emission and absorption of photons

17. The energy levels in a hydrogen atom, according to Bohr's model, are quantized. This means: — Electrons can only possess discrete, specific energy values.

18. What is the fundamental assumption of Bohr's atomic model regarding electron orbits? — Electrons orbit the nucleus only in specific, quantized energy levels.

19. The Bohr model postulates that electrons revolve around the nucleus in specific orbits without losing energy. These orbits are called: — Stationary states

20. Which of the following quantities is quantized in the Bohr model? — All of the above

21. What is the unit of angular momentum for an electron in a Bohr orbit? — nh/2π

22. The angular momentum of an electron in the second orbit (n=2) of hydrogen is: — h/π

23. The Bohr model successfully explained the spectrum of: — All atoms with one electron

24. The Balmer series of the hydrogen spectrum lies in which region of the electromagnetic spectrum? — Visible

25. What happens to the energy of an electron as it moves to a higher energy level (larger n) in a hydrogen atom? — It increases and becomes less negative (closer to zero).

26. The Bohr model is a semi-classical model because: — It combines classical concepts (like orbits) with quantum postulates (like quantized energy).

27. Which spectral series of hydrogen is observed when electrons transition from higher states to n=4? — Brackett

28. Which spectral series of hydrogen lies in the far-infrared region? — Humphreys

29. Which spectral series of hydrogen is observed in the infrared region? — Paschen series

30. The Bohr model provides a good approximation for the energy levels of: — Hydrogen-like species (e.g., He⁺, Li²⁺)

31. The Bohr model fails to explain the spectra of: — Atoms with more than one electron

32. The angular momentum of an electron in an orbit is quantized according to the Bohr model. This quantization is expressed as: — mvr = nh/2π

33. The Lyman series of the hydrogen spectrum corresponds to transitions from higher energy levels to which principal quantum number? — n=1

34. If an electron in a hydrogen atom is in the n=3 state, it can emit photons corresponding to transitions to which lower states? — n=1 and n=2

35. The ionization energy of hydrogen is the energy required to transition an electron from: — n=1 to n=∞

36. The spectral lines in the Pfund series of hydrogen correspond to transitions to which principal quantum number? — n=5

37. Which of the following transitions will result in the emission of the highest energy photon? — n=2 to n=1

38. What is the wave number (1/λ) of the spectral line emitted when an electron transitions from n=3 to n=2 in hydrogen? — R_H (1/2² - 1/3²)

39. What is the radius of the nth orbit in a hydrogen atom, given by the Bohr model? — r_n = a_0 * n²

40. The constant α in the velocity formula v_n = (cα)/n is known as: — Fine-structure constant

41. The term 'spectrum' in the context of the hydrogen atom refers to: — The pattern of wavelengths of light emitted or absorbed by the atom.

42. What does R_H represent in the Rydberg formula for hydrogen's spectral lines? — The Rydberg constant

43. The frequency of the emitted radiation during an electronic transition is proportional to: — The difference in energy between the two levels.

44. The energy of the emitted photon is equal to the difference in energy between: — The initial and final orbits.

45. What does the symbol 'n' represent in the Bohr model's energy level formula (E = -13.6/n² eV)? — The principal quantum number

46. A transition from n=5 to n=2 in hydrogen atom would result in the emission of a photon in which region? — Visible

47. What is the velocity of an electron in the nth Bohr orbit of a hydrogen atom? — v_n = (cα)/n

48. According to the Bohr model, when does an electron emit or absorb energy? — When it moves between orbits.

49. If the electron in a hydrogen atom jumps from n=∞ to n=1, the energy absorbed is: — 13.6 eV

50. The energy of a photon emitted or absorbed during a transition between two energy levels E_i and E_f is given by:|E_f - E_i|. The Bohr model states that this energy difference must be: — Quantized in multiples of hν

Spectrum of hydrogen atom and Bohr model basics - One Line Questions