TRB PG Assistant - Effective nuclear charge and Slater rules Online Test (MCQ Quiz)

1. What is the definition of effective nuclear charge (Zeff)?

A) The total positive charge of the nucleus. B) The actual nuclear charge experienced by an electron in a multi-electron atom. C) The charge of the outermost electron. D) The charge of the inner shell electrons.

2. Which factor primarily reduces the effective nuclear charge experienced by an electron?

A) The number of protons in the nucleus. B) The attraction to the nucleus. C) Repulsion from other electrons (shielding effect). D) The charge of the outermost electron shell.

3. What does Slater's rules aim to calculate?

A) The atomic radius of an element. B) The ionization energy of an element. C) The shielding constant (S) for an electron. D) The electronegativity of an atom.

4. According to Slater's rules, what is the shielding value (S) for an electron in the 1s orbital of a hydrogen atom?

A) 0 B) 0.30 C) 0.35 D) 1.00

5. In Slater's rules, electrons in the same principal quantum shell (n) but different subshells (l) contribute how much to the shielding constant (S) for each other?

A) 0.30 B) 0.35 C) 0.85 D) 1.00

6. For an electron in the (n) shell, what is the shielding contribution from electrons in the (n-1) shell according to Slater's rules?

A) 0.30 B) 0.35 C) 0.85 D) 1.00

7. What is the shielding contribution from electrons in shells with principal quantum number (n-2) or lower, according to Slater's rules?

A) 0.30 B) 0.35 C) 0.85 D) 1.00

8. How is the effective nuclear charge (Zeff) calculated using the shielding constant (S) and the atomic number (Z)?

A) Zeff = Z + S B) Zeff = Z - S C) Zeff = S - Z D) Zeff = Z * S

9. Which electron group is considered when calculating the shielding constant (S) for a 3d electron in Slater's rules?

A) 1s, 2s, 2p B) 3s, 3p C) 4s, 4p D) All electrons in shells n-1 and n-2

10. What is the atomic number (Z) of Sodium (Na)?

A) 10 B) 11 C) 12 D) 23

11. Calculate the shielding constant (S) for a 3s electron in Sodium (Na) using Slater's rules. Sodium configuration: [Ne] 3s^1.

A) 0.30 B) 0.85 C) 8.80 D) 10.00

12. Calculate the effective nuclear charge (Zeff) for a 3s electron in Sodium (Na).

A) 1.20 B) 10.15 C) 11.00 D) 2.20

13. How does the effective nuclear charge generally change across a period in the periodic table?

A) Decreases B) Increases C) Remains constant D) Fluctuates unpredictably

14. How does the effective nuclear charge generally change down a group in the periodic table?

A) Decreases B) Increases C) Remains constant D) Fluctuates unpredictably

15. Which of the following electrons experiences the highest effective nuclear charge?

A) 1s electron in Helium B) 2s electron in Lithium C) 2p electron in Carbon D) 3s electron in Sodium

16. What is the primary reason for the increase in effective nuclear charge across a period?

A) Increase in the number of electron shells. B) Addition of electrons to the same principal energy level, increasing shielding. C) Addition of protons to the nucleus with minimal increase in shielding. D) Decrease in the atomic number.

17. What is the primary reason for the decrease in effective nuclear charge down a group?

A) Increase in the number of electron shells, leading to greater shielding. B) Decrease in the number of protons in the nucleus. C) Addition of electrons to different principal energy levels. D) Increase in the atomic number.

18. In Slater's rules, what is the shielding contribution of a 1s electron for another 1s electron in the same atom?

A) 0.30 B) 0.35 C) 0.85 D) 1.00

19. Consider an electron in the 3p orbital of Phosphorus (Z=15). Which electrons contribute significantly to shielding it according to Slater's rules?

A) 1s electrons only B) 2s and 2p electrons only C) 3s electrons and electrons in shells n-1 and lower D) 4s electrons

20. Slater's rules provide an approximation. What is a known limitation of these rules?

A) They overestimate shielding for d and f electrons. B) They underestimate shielding for s and p electrons. C) They do not account for the principal quantum number. D) They are only applicable to transition metals.

21. What is the atomic number (Z) of Chlorine (Cl)?

A) 16 B) 17 C) 18 D) 35.5

22. Calculate the shielding constant (S) for a 3p electron in Chlorine (Cl) using Slater's rules. Chlorine configuration: [Ne] 3s^2 3p^5.

A) 10.75 B) 11.70 C) 13.25 D) 16.00

23. Calculate the effective nuclear charge (Zeff) for a 3p electron in Chlorine (Cl).

A) 5.25 B) 6.25 C) 4.25 D) 7.25

24. How does the effective nuclear charge experienced by a 2s electron in Lithium (Li) compare to a 1s electron in Helium (He)?

A) Zeff(Li 2s) > Zeff(He 1s) B) Zeff(Li 2s) < Zeff(He 1s) C) Zeff(Li 2s) = Zeff(He 1s) D) Cannot be determined without more information.

25. The shielding effect is also known as:

A) Penetration effect B) Screening effect C) Resonance effect D) Inductive effect

26. Which of the following is NOT a factor considered in Slater's rules for calculating shielding?

A) Principal quantum number (n) of the electron. B) Number of electrons in the same shell (n). C) Number of electrons in the shell (n-1). D) Number of electrons in the shell (n-2) and lower.

27. What is the approximate shielding constant (S) for a 4s electron in Potassium (K) [Ar] 4s^1 using Slater's rules?

A) 0.30 B) 0.85 C) 10.00 D) 17.00

28. Calculate the effective nuclear charge (Zeff) for a 4s electron in Potassium (K).

A) 0.70 B) 1.00 C) 17.15 D) 18.00

29. Why is the shielding contribution from electrons in the same shell (n) less effective than from electrons in inner shells (n-1)?

A) Outer shell electrons are closer to the nucleus. B) Outer shell electrons are further from the nucleus and do not penetrate as effectively. C) Inner shell electrons have a higher positive charge. D) Outer shell electrons repel each other more strongly.

30. What is the atomic number (Z) of Oxygen (O)?

A) 7 B) 8 C) 9 D) 16

31. Calculate the shielding constant (S) for a 2p electron in Oxygen (O) [He] 2s^2 2p^4 using Slater's rules.

A) 1.70 B) 1.90 C) 2.00 D) 2.70

32. Calculate the effective nuclear charge (Zeff) for a 2p electron in Oxygen (O).

A) 6.30 B) 6.10 C) 5.30 D) 7.00

33. Which statement best describes the trend of effective nuclear charge (Zeff) in transition metals?

A) Zeff increases significantly with each added d electron. B) Zeff increases slightly with each added d electron due to poor shielding by d electrons. C) Zeff decreases with each added d electron. D) Zeff remains constant for transition metals.

34. In Slater's rules, for an electron in a d or f orbital, what is the shielding contribution from other electrons in the same (n) shell?

A) 0.30 B) 0.35 C) 0.85 D) 1.00

35. Consider a 3d electron in Scandium (Sc), Z=21. Configuration: [Ar] 3d^1 4s^2. What is the shielding contribution from the 4s electrons to the 3d electron?

A) 0.30 B) 0.35 C) 0.85 D) 1.00

36. Calculate the shielding constant (S) for a 3d electron in Scandium (Sc) using Slater's rules. Other electrons: [Ar] (18 electrons).

A) 10.15 B) 15.00 C) 18.35 D) 21.00

37. Calculate the effective nuclear charge (Zeff) for a 3d electron in Scandium (Sc).

A) 10.85 B) 11.00 C) 5.85 D) 2.65

38. What is the atomic number (Z) of Iron (Fe)?

A) 25 B) 26 C) 27 D) 56

39. Calculate the shielding constant (S) for a 3d electron in Iron (Fe) [Ar] 3d^6 4s^2 using Slater's rules. Consider the 3d electron.

A) 18.00 B) 21.50 C) 22.05 D) 23.00

40. Calculate the effective nuclear charge (Zeff) for a 3d electron in Iron (Fe).

A) 4.05 B) 3.95 C) 13.95 D) 18.00

41. How does the effective nuclear charge experienced by a 3d electron change from Scandium (Sc) to Iron (Fe)?

A) It increases significantly. B) It increases slightly. C) It decreases. D) It remains approximately the same.

42. What is the primary effect of the poor shielding by d and f electrons on the effective nuclear charge?

A) It leads to a significant decrease in Zeff for outer electrons. B) It leads to a slight increase in Zeff for outer electrons. C) It causes Zeff to become negative. D) It makes Zeff independent of the number of d or f electrons.

43. Which of the following is the correct order of shielding effectiveness for electrons in different shells towards an outer electron?

A) (n-1) > (n-2) > same n B) same n > (n-1) > (n-2) C) (n-2) > (n-1) > same n D) same n > (n-2) > (n-1)

44. What is the atomic number (Z) of Neon (Ne)?

A) 9 B) 10 C) 11 D) 20

45. Calculate the shielding constant (S) for a 1s electron in Neon (Ne) using Slater's rules.

A) 0.30 B) 0.35 C) 0.70 D) 1.00

46. Calculate the effective nuclear charge (Zeff) for a 1s electron in Neon (Ne).

A) 9.30 B) 9.65 C) 9.00 D) 8.00

47. What is the atomic number (Z) of Argon (Ar)?

A) 17 B) 18 C) 19 D) 40

48. Calculate the shielding constant (S) for a 3s electron in Argon (Ar) [Ne] 3s^2 3p^6 using Slater's rules.

A) 10.75 B) 11.70 C) 15.00 D) 16.00

49. Calculate the effective nuclear charge (Zeff) for a 3s electron in Argon (Ar).

A) 7.30 B) 6.30 C) 18.00 D) 11.70

50. Which of the following elements has the highest effective nuclear charge for its valence electrons?

A) Lithium (Li) B) Beryllium (Be) C) Boron (B) D) Carbon (C)

Effective nuclear charge and Slater rules - Online Test

Test Results