MDCAT XI Chemistry Atomic Structure Online Test 2026

1. The splitting of a spectrum line into several components by the application of a magnetic feild is called

2. The failure of Bohr's model of atom is due to his assumption:

3. Energy of electron in hydrogen atom at n=3is:

4. The wavelength of radiation emitted when an electron jumps from n = 5 to n = 2 in hydrogen is closest to: (Rydberg constant R = 1.097 * 10 ^ 7, m ^ - 1 )

5. Number of nodal planes in a p-orbital is:

6. The main limitation of Rutherford’s model was its failure to explain:

7. Which particle shows diffraction pattern in Davisson–Germer experiment?

8. Which quantum number explains the splitting of spectral lines in magnetic field?

9. Which statement is incorrect about an orbital?

10. Number of orbitals in the d-subshell is:

11. The uncertainty principle becomes most significant for:

12. Maximum number of electrons having n=3is:

13. Which particle has the shortest de Broglie wavelength when moving with the same velocity?

14. Which experiment confirmed the wave nature of electrons?

15. The spectrum obtained when white light passes through hydrogen gas is:

16. Which of the following sets of quantum numbers is not allowed?

17. If uncertainty in position of an electron is decreased, the uncertainty in its momentum will:

18. The de Broglie wavelength of an electron becomes double if:

19. The number of radial nodes in the 4d orbital is:

20. Which transition in a hydrogen atom emits the most energetic photon?

21. Which pair of ions is not isoelectronic?

22. The wavelength of a photon emitted when an electron in hydrogen drops from n=5 to n=3 is:

23. The total number of electrons in n=3 shell of neutral sulfur (S) atom is:

24. The energy of an electron in n=3 state of hydrogen atom is:

25. Which of the following statements is correct?

26. Relative speed of α-particles and γ-rays in vacuum:

27. Which has greater momentum for equal energy?

28. Which pair is correct in terms of energy and ionizing power?

29. Which set of quantum numbers is invalid?

30. Which element shows half-filled d-subshell due to stability (Hund + Aufbau exceptions)?

31. Which of the following pairs follows the n+l rule correctly for filling order?

32. According to the n+l rule, which orbital is filled first?

33. According to the Pauli Exclusion Principle, which of the following is NOT possible?

34. The first anomalous configuration in the 3d series is observed for:

35. Which element is isoelectronic with Ne?

36. Which element has the ground-state configuration [Ar] 4s¹ 3d⁵?

37. According to Bonr's concept, electron revoives around the nucieus in circular orbit. Later on, it was proved that electron did not move in single plane but in:

38. The value of Rydberg constant is:

39. Which statement about Heisenberg’s Uncertainty Principle is correct?

40. The correct order of increasing energy of orbitals is:

41. The ratio of energy and the frequency of photon is equals to:

42. Which of the following has the lowest e/m value?

43. The ratio of wavelengths of first line of Lyman series to first line of Balmer series is:

44. If uncertainty in position of an electron is zero, then uncertainty in momentum will be:

45. The wavelength of the photon emitted when an electron drops from n=4to n=2 in hydrogen is:

46. Which of the following shows the correct order of increasing first ionization energy?

47. The energy difference between n=3 and n=2 levels of He⁺ is:

48. Which of the following is not a postulate of Bohr’s theory?

49. An orbital with two angular nodes and one radial node belongs to:

50. Which rule explains the pairing of electrons in orbitals?