Atomic Structure and Electron Configuration - AP Chemistry

1. Determine the number of electrons in a magnesium ion (Mg$^{2+}$).

   10 electrons. Magnesium loses 2 electrons to form $Mg^{2+}$, leaving 10 electrons.

2. What is the formula for calculating the number of neutrons?

   Neutrons = Mass number - Atomic number. Mass number includes both protons and neutrons, so subtract protons to get neutrons.

3. Identify the quantum number that describes the shape of an orbital.

   Azimuthal quantum number ($l$). The $l$ value determines whether an orbital is s, p, d, or f type.

4. What is the spin quantum number ($m_s$) possible values?

   $+\frac{1}{2}$ or $-\frac{1}{2}$. Represents the two possible spin orientations of an electron.

5. State the element with electron configuration $[Ne] 3s^2 3p^5$.

   Chlorine (Cl). The configuration $[Ne] 3s^2 3p^5$ indicates 17 total electrons, which is chlorine.

6. Identify the charge of a neutron.

   Neutral charge (0). Neutrons are electrically neutral particles in the nucleus.

7. What is the electron configuration of helium?

   $1s^2$. Helium has 2 electrons, both filling the 1s orbital.

8. How many electrons can the n=2 energy level hold?

   8 electrons. The $n=2$ level has 2s and 2p subshells: $2 + 6 = 8$ electrons total.

9. What is the maximum number of orbitals in the n=3 energy level?

   9 orbitals. The $n=3$ level has s, p, and d subshells: $1 + 3 + 5 = 9$ orbitals.

10. What is the maximum number of orbitals in the n=3 energy level?

    9 orbitals. The $n=3$ level has s, p, and d subshells: $1 + 3 + 5 = 9$ orbitals.

11. State the element with electron configuration $[Ne] 3s^2 3p^5$.

    Chlorine (Cl). The configuration $[Ne] 3s^2 3p^5$ indicates 17 total electrons, which is chlorine.

12. What is the electron configuration of argon?

    $1s^2 2s^2 2p^6 3s^2 3p^6$. Argon has 18 electrons completely filling through the 3p subshell.

13. What is the electron configuration of an oxygen ion (O$^{2-}$)?

    $1s^2 2s^2 2p^6$. Oxide ion gains 2 electrons, achieving neon's electron configuration.

14. What does the magnetic quantum number ($m_l$) indicate?

    Orientation of an orbital. Describes which specific orbital within a subshell the electron occupies.

15. Identify the quantum number that describes the shape of an orbital.

    Azimuthal quantum number ($l$). The $l$ value determines whether an orbital is s, p, d, or f type.

16. State the maximum number of electrons in the n=4 energy level.

    32 electrons. The $n=4$ level can hold $2n^2 = 2(4)^2 = 32$ electrons total.

17. What is the electron configuration of helium?

    $1s^2$. Helium has 2 electrons, both filling the 1s orbital.

18. Identify the number of unpaired electrons in a carbon atom.

    2 unpaired electrons. Carbon's 2p subshell has 2 electrons, both unpaired by Hund's rule.

19. What is the electron configuration notation for neon?

    $1s^2 2s^2 2p^6$. Neon has 10 electrons filling through the 2p subshell completely.

20. What is the maximum number of orbitals in the n=3 energy level?

    9 orbitals. The $n=3$ level has s, p, and d subshells: $1 + 3 + 5 = 9$ orbitals.

21. What does the magnetic quantum number ($m_l$) indicate?

    Orientation of an orbital. Describes which specific orbital within a subshell the electron occupies.

22. State the element with electron configuration $[Ne] 3s^2 3p^5$.

    Chlorine (Cl). The configuration $[Ne] 3s^2 3p^5$ indicates 17 total electrons, which is chlorine.

23. What is the electron configuration for sulfur?

    $1s^2 2s^2 2p^6 3s^2 3p^4$. Sulfur has 16 electrons, with 4 electrons in the 3p subshell.

24. What is the electron configuration of an oxygen ion (O$^{2-}$)?

    $1s^2 2s^2 2p^6$. Oxide ion gains 2 electrons, achieving neon's electron configuration.

25. What is the formula for calculating the number of neutrons?

    Neutrons = Mass number - Atomic number. Mass number includes both protons and neutrons, so subtract protons to get neutrons.

26. Find the total number of electrons in a neon atom.

    10 electrons. Neon's atomic number is 10, so neutral atoms have 10 electrons.

27. What is the azimuthal quantum number for p orbitals?

    $l = 1$. P orbitals correspond to $l = 1$ in the azimuthal quantum number system.

28. Determine the electron configuration for sodium.

    $1s^2 2s^2 2p^6 3s^1$. Sodium has 11 electrons, filling through 3s with one electron.

29. What is the electron configuration of potassium?

    $1s^2 2s^2 2p^6 3s^2 3p^6 4s^1$. Potassium has 19 electrons, with the last electron in the 4s orbital.

30. What is the electron configuration of argon?

    $1s^2 2s^2 2p^6 3s^2 3p^6$. Argon has 18 electrons completely filling through the 3p subshell.

31. What is the electron configuration for a fluoride ion (F-)?

    $1s^2 2s^2 2p^6$. Fluoride ion gains one electron, achieving neon's electron configuration.

32. What does the Aufbau principle describe?

    Electron filling order in orbitals. Electrons fill lowest energy orbitals first before higher energy ones.

33. State the maximum number of electrons in the n=4 energy level.

    32 electrons. The $n=4$ level can hold $2n^2 = 2(4)^2 = 32$ electrons total.

34. How many electrons can the n=2 energy level hold?

    8 electrons. The $n=2$ level has 2s and 2p subshells: $2 + 6 = 8$ electrons total.

35. What is the electron configuration for a fluoride ion (F-)?

    $1s^2 2s^2 2p^6$. Fluoride ion gains one electron, achieving neon's electron configuration.

36. What is the principal quantum number symbolized by?

    n. The principal quantum number indicates the energy level or shell.

37. Which principle states that no two electrons can have the same set of quantum numbers?

    Pauli Exclusion Principle. Each electron must have a unique set of four quantum numbers.

38. Identify the number of orbitals in a d subshell.

    5 orbitals. The d subshell contains 5 degenerate orbitals.

39. What is the electron configuration notation for neon?

    $1s^2 2s^2 2p^6$. Neon has 10 electrons filling through the 2p subshell completely.

40. What is the electron configuration of carbon?

    $1s^2 2s^2 2p^2$. Carbon has 6 electrons: 2 in 1s, 2 in 2s, and 2 in 2p.

41. What is the electron configuration notation for neon?

    $1s^2 2s^2 2p^6$. Neon has 10 electrons filling through the 2p subshell completely.

42. What is the atomic number of an element?

    The number of protons in the nucleus. Defines the element's identity and equals the number of electrons in neutral atoms.

43. What is the electron configuration of helium?

    $1s^2$. Helium has 2 electrons, both filling the 1s orbital.

44. Identify the quantum number that describes the shape of an orbital.

    Azimuthal quantum number ($l$). The $l$ value determines whether an orbital is s, p, d, or f type.

45. Determine the number of electrons in a magnesium ion (Mg$^{2+}$).

    10 electrons. Magnesium loses 2 electrons to form $Mg^{2+}$, leaving 10 electrons.

46. What is the electron configuration for sulfur?

    $1s^2 2s^2 2p^6 3s^2 3p^4$. Sulfur has 16 electrons, with 4 electrons in the 3p subshell.

47. Identify the maximum number of electrons in an f subshell.

    14 electrons. The f subshell has 7 orbitals, each holding 2 electrons maximum.

48. Identify the number of orbitals in a d subshell.

    5 orbitals. The d subshell contains 5 degenerate orbitals.

49. What is the shape of an s orbital?

    Spherical. All s orbitals have spherical symmetry around the nucleus.

50. What does the magnetic quantum number ($m_l$) indicate?

    Orientation of an orbital. Describes which specific orbital within a subshell the electron occupies.

51. What is the atomic number of an element?

    The number of protons in the nucleus. Defines the element's identity and equals the number of electrons in neutral atoms.

52. What is the electron configuration of carbon?

    $1s^2 2s^2 2p^2$. Carbon has 6 electrons: 2 in 1s, 2 in 2s, and 2 in 2p.

53. State the number of valence electrons in oxygen.

    6 valence electrons. Oxygen is in group 16, so it has 6 electrons in its outermost shell.

54. Which principle states that no two electrons can have the same set of quantum numbers?

    Pauli Exclusion Principle. Each electron must have a unique set of four quantum numbers.

55. State the value range for the azimuthal quantum number ($l$).

    0 to $n-1$. For a given $n$, the azimuthal quantum number ranges from 0 to $n-1$.

56. State the element with the electron configuration $[Xe] 6s^2 4f^{14} 5d^{10} 6p^2$.

    Lead (Pb). The configuration ends in $6p^2$, characteristic of lead in group 14.

57. Identify the charge of a neutron.

    Neutral charge (0). Neutrons are electrically neutral particles in the nucleus.

58. Identify the number of valence electrons in nitrogen.

    5 valence electrons. Nitrogen is in group 15, so it has 5 valence electrons.

59. What is the spin quantum number ($m_s$) possible values?

    $+\frac{1}{2}$ or $-\frac{1}{2}$. Represents the two possible spin orientations of an electron.

60. State the number of valence electrons in oxygen.

    6 valence electrons. Oxygen is in group 16, so it has 6 electrons in its outermost shell.

61. Find the number of electrons in a neutral chlorine atom.

    17 electrons. Chlorine's atomic number is 17, so neutral atoms have 17 electrons.

62. What is the electron configuration of a calcium ion (Ca$^{2+}$)?

    $1s^2 2s^2 2p^6 3s^2 3p^6$. Calcium loses 2 electrons to form $Ca^{2+}$, giving argon's configuration.

63. Identify the number of unpaired electrons in a carbon atom.

    2 unpaired electrons. Carbon's 2p subshell has 2 electrons, both unpaired by Hund's rule.

64. Find the number of electrons in a neutral chlorine atom.

    17 electrons. Chlorine's atomic number is 17, so neutral atoms have 17 electrons.

65. Determine the electron configuration for sodium.

    $1s^2 2s^2 2p^6 3s^1$. Sodium has 11 electrons, filling through 3s with one electron.

66. Identify the charge of a neutron.

    Neutral charge (0). Neutrons are electrically neutral particles in the nucleus.

67. What is the azimuthal quantum number for p orbitals?

    $l = 1$. P orbitals correspond to $l = 1$ in the azimuthal quantum number system.

68. What is the electron configuration of argon?

    $1s^2 2s^2 2p^6 3s^2 3p^6$. Argon has 18 electrons completely filling through the 3p subshell.

69. Determine the number of electrons in a magnesium ion ($Mg^{2+}$).

    10 electrons. Magnesium loses 2 electrons to form $Mg^{2+}$, leaving 10 electrons.

70. Determine the number of unpaired electrons in oxygen.

    2 unpaired electrons. Oxygen's 2p subshell has 4 electrons: 2 paired and 2 unpaired by Hund's rule.

71. State the value range for the azimuthal quantum number ($l$).

    0 to $n-1$. For a given $n$, the azimuthal quantum number ranges from 0 to $n-1$.

72. Identify the maximum number of electrons in an f subshell.

    14 electrons. The f subshell has 7 orbitals, each holding 2 electrons maximum.

73. State the element with the electron configuration $[Xe] 6s^2 4f^{14} 5d^{10} 6p^2$.

    Lead (Pb). The configuration ends in $6p^2$, characteristic of lead in group 14.

74. State the maximum number of electrons in the n=4 energy level.

    32 electrons. The $n=4$ level can hold $2n^2 = 2(4)^2 = 32$ electrons total.

75. Identify the number of valence electrons in nitrogen.

    5 valence electrons. Nitrogen is in group 15, so it has 5 valence electrons.

76. Find the number of electrons in a neutral chlorine atom.

    17 electrons. Chlorine's atomic number is 17, so neutral atoms have 17 electrons.

77. Determine the number of unpaired electrons in oxygen.

    2 unpaired electrons. Oxygen's 2p subshell has 4 electrons: 2 paired and 2 unpaired by Hund's rule.

78. What is the electron configuration for aluminum?

    $1s^2 2s^2 2p^6 3s^2 3p^1$. Aluminum has 13 electrons, with 1 electron in the 3p subshell.

79. What is the electron configuration of a calcium ion (Ca$^{2+}$)?

    $1s^2 2s^2 2p^6 3s^2 3p^6$. Calcium loses 2 electrons to form $Ca^{2+}$, giving argon's configuration.

80. What is the electron configuration of a calcium ion (Ca$^{2+}$)?

    $1s^2 2s^2 2p^6 3s^2 3p^6$. Calcium loses 2 electrons to form $Ca^{2+}$, giving argon's configuration.

81. Determine the number of electrons in a magnesium ion (Mg$^{2+}$).

    10 electrons. Magnesium loses 2 electrons to form $Mg^{2+}$, leaving 10 electrons.

82. What is the principal quantum number symbolized by?

    n. The principal quantum number indicates the energy level or shell.

83. Identify the number of valence electrons in nitrogen.

    5 valence electrons. Nitrogen is in group 15, so it has 5 valence electrons.

84. What is the shape of an s orbital?

    Spherical. All s orbitals have spherical symmetry around the nucleus.

85. Which principle states that no two electrons can have the same set of quantum numbers?

    Pauli Exclusion Principle. Each electron must have a unique set of four quantum numbers.

86. What is the electron configuration of an oxygen ion (O$^{2-}$)?

    $1s^2 2s^2 2p^6$. Oxide ion gains 2 electrons, achieving neon's electron configuration.

87. What is the atomic number of an element?

    The number of protons in the nucleus. Defines the element's identity and equals the number of electrons in neutral atoms.

88. How many electrons can the n=2 energy level hold?

    8 electrons. The $n=2$ level has 2s and 2p subshells: $2 + 6 = 8$ electrons total.

89. How many electrons can occupy a single orbital?

    2 electrons. Maximum capacity per orbital due to Pauli Exclusion Principle.

90. What is the electron configuration for sulfur?

    $1s^2 2s^2 2p^6 3s^2 3p^4$. Sulfur has 16 electrons, with 4 electrons in the 3p subshell.

91. What is the electron configuration of potassium?

    $1s^2 2s^2 2p^6 3s^2 3p^6 4s^1$. Potassium has 19 electrons, with the last electron in the 4s orbital.

92. State the value range for the azimuthal quantum number ($l$).

    0 to $n-1$. For a given $n$, the azimuthal quantum number ranges from 0 to $n-1$.

93. State the element with the electron configuration $[Xe] 6s^2 4f^{14} 5d^{10} 6p^2$.

    Lead (Pb). The configuration ends in $6p^2$, characteristic of lead in group 14.

94. What is the principal quantum number symbolized by?

    n. The principal quantum number indicates the energy level or shell.

95. Identify the number of unpaired electrons in a carbon atom.

    2 unpaired electrons. Carbon's 2p subshell has 2 electrons, both unpaired by Hund's rule.

96. Find the total number of electrons in a neon atom.

    10 electrons. Neon's atomic number is 10, so neutral atoms have 10 electrons.

97. What does the Aufbau principle describe?

    Electron filling order in orbitals. Electrons fill lowest energy orbitals first before higher energy ones.

98. What is the electron configuration of carbon?

    $1s^2 2s^2 2p^2$. Carbon has 6 electrons: 2 in 1s, 2 in 2s, and 2 in 2p.

99. Which rule states that electrons fill degenerate orbitals singly first?

    Hund's Rule. Maximizes unpaired electrons before pairing to minimize electron-electron repulsion.

100. What is the electron configuration of potassium?

     $1s^2 2s^2 2p^6 3s^2 3p^6 4s^1$. Potassium has 19 electrons, with the last electron in the 4s orbital.

101. What is the electron configuration for a fluoride ion (F-)?

     $1s^2 2s^2 2p^6$. Fluoride ion gains one electron, achieving neon's electron configuration.

102. What is the azimuthal quantum number for p orbitals?

     $l = 1$. P orbitals correspond to $l = 1$ in the azimuthal quantum number system.

103. How many electrons can occupy a single orbital?

     2 electrons. Maximum capacity per orbital due to Pauli Exclusion Principle.

104. What is the formula for calculating the number of neutrons?

     Neutrons = Mass number - Atomic number. Mass number includes both protons and neutrons, so subtract protons to get neutrons.

105. Which rule states that electrons fill degenerate orbitals singly first?

     Hund's Rule. Maximizes unpaired electrons before pairing to minimize electron-electron repulsion.

106. Determine the number of unpaired electrons in oxygen.

     2 unpaired electrons. Oxygen's 2p subshell has 4 electrons: 2 paired and 2 unpaired by Hund's rule.

107. State the number of valence electrons in oxygen.

     6 valence electrons. Oxygen is in group 16, so it has 6 electrons in its outermost shell.

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