Class 11 Chemistry — Chapter 2: Structure of Atom Online Test

1. For hydrogen atom, the ratio of radii of 1st and 3rd orbit is:

2. The number of radial nodes in 5d orbital is:

3. The ionization energy of hydrogen atom in the ground state is:

4. The electronic configuration of neon (Z=10) is:

5. The electronic configuration of helium (Z=2) is:

6. Why do electrons prefer to occupy different orbitals of equal energy before pairing?

7. When two subshells have the same value, the one that fills first is the one with:

8. Which d-orbitals have lobes oriented between the axes (at 45° angles)?

9. The radial probability distribution curve of a 2s orbital shows:

10. The value of is associated with:

11. The azimuthal quantum number primarily determines the:

12. If , how many orbitals are possible in that shell?

13. The three dumbbell-shaped orbitals oriented along x, y, and z axes are:

14. What physical meaning does the wave function itself have?

15. The first line of the Brackett series corresponds to which transition?

16. Which equation represents Einstein’s photoelectric effect?

17. What is the wavelength of a radio wave with frequency ?

18. Which of the following is a correct postulate of Bohr’s atomic model?

19. In Chadwick’s experiment, which element was bombarded with alpha particles to discover the neutron?

20. What conclusion did Rutherford draw from the gold foil experiment?

1. Which statement is true about the nodal plane in a p-orbital?

2. The Paschen series corresponds to transitions of electrons ending at:

3. Which statement is a limitation of Rutherford’s nuclear model?

4. The speed of electromagnetic waves in a medium is less than in vacuum because:

5. In Bohr’s orbit, electrons are assumed to:

6. Who first proposed the concept of atom as an indivisible particle?

7. According to Bohr’s model, electrons revolve around the nucleus in:

8. Upon forming cations for first-row transition metals, electrons are removed first from:

9. The maximum number of electrons that can occupy all five d-orbitals is:

10. The number of angular nodes in 4d orbital is:

11. Which statement best summarizes the limitation of Bohr’s theory?

12. What is the mass of a proton?

13. What is the maximum number of electrons that can occupy a single orbital?

14. Which unit combination correctly represents frequency?

15. Which of the following d-orbitals has a different shape compared to the others?

16. Which type of spectrum shows bright lines against a dark background?

17. The probability distribution of a p-orbital is:

18. The electronic configuration of helium (Z=2) is:

19. The time-independent Schrödinger equation is written as:

20. Which statement correctly describes Bohr’s concept of an orbit?

21. What is the frequency of radiation emitted when an electron jumps from to in hydrogen?

22. Which scientist first demonstrated the wave nature of light through the double-slit experiment?

23. According to Thomson’s model, most of an atom’s mass is:

24. The wave–particle duality of electron means:

25. Which of the following spectral series has the shortest wavelength limit?

26. The splitting of white light into its component colors is called:

27. The stopping potential in a photoelectric experiment is directly related to:

28. Which branch of physics deals with the study of spectra?

29. Why are half-filled and fully filled subshells more stable?

30. For a given element and electronic transition, how do emission and absorption wavelengths compare?

1. Which of the following represents a stable noble gas configuration?

2. If , how many orbitals are possible in that shell?

3. The five d-orbitals have orientations described by:

4. Which of the following spectral series has the shortest wavelength limit?

5. The time-independent Schrödinger equation is written as:

6. Which subatomic particle contributes to both the mass and stability of the nucleus but not to the atomic number?

7. Hund’s rule of maximum multiplicity states that:

8. The electronic configuration of chromium (Z=24) is anomalous because it is:

9. What kind of spectrum is produced when white light passes through a cold gas before entering a spectroscope?

10. Which noble gas configuration is equivalent to neon (Z=10)?

11. The uncertainty in the position of an electron is . What is the minimum uncertainty in its momentum (h = )?

12. How does increasing gas pressure typically affect spectral lines (emission or absorption)?

13. Which of the following phenomena is explained by particle nature of light?

14. If the velocity of a wave is constant, what happens when the wavelength decreases?

15. The actual configuration of molybdenum (Z=42) is:

16. Which of the following is a major limitation of Bohr’s model?

17. Why does the 1s orbital of hydrogen contain only one electron in the ground state?

18. The maximum number of electrons that can be accommodated in an orbital is:

19. What is the wavelength of the first line of the Lyman series ()?

20. The probability distribution of a p-orbital is:

21. The ionization energy of hydrogen atom in the ground state is:

22. The orientation of orbital is:

23. Which property of neutrons makes them highly useful in nuclear reactions?

24. Which limitation of Bohr’s model is correct?

25. Which of the following quantum numbers decides the shape of an orbital?

26. Why was the concept of orbit replaced by orbital?

27. The Rydberg formula for hydrogen spectral lines is:

28. Which scientist first demonstrated the wave nature of light through the double-slit experiment?

29. The velocity of an electron in the first Bohr orbit of hydrogen is approximately:

30. The Lyman series of hydrogen spectral lines lies in which region of the electromagnetic spectrum?

31. The ground-state configuration of chromium (Z = 24) is:

32. The electronic configuration [Ar] 3d¹⁰ 4s² 4p¹ belongs to:

33. The number of angular nodes in 4d orbital is:

34. What is the velocity of a wave with frequency and wavelength ?

35. Which reaction represents the production of neutrons in Chadwick’s experiment?

36. What physical meaning does the wave function itself have?

37. The electronic configuration of neon (Z=10) is:

38. Which quantum number primarily determines the size of an orbital?

39. What is meant by the term “spectrum” in physics?

40. In quantum mechanics, an orbital is defined as:

41. Which of the following orbitals has a spherical shape but different size compared to 1s?

42. The splitting of spectral lines in a magnetic field is explained by:

43. The possible values of the spin quantum number () are:

44. The Pfund series of hydrogen corresponds to transitions to:

45. The magnetic quantum number () signifies:

46. Which observation cannot be explained by classical wave theory but is explained by Planck’s quantum theory?

47. A stellar spectrum shows strong dark Na “D” lines near and . This most directly indicates:

48. Increasing light intensity above threshold frequency will:

49. Which letter notation corresponds to ?

50. Which of the following sets correctly matches the charge of subatomic particles?