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VSEPR Flashcards: Molecular Geometry & Bond Angles

Practice VSEPR shapes, electron geometry, lone pairs, AXE notation, and ideal bond angles with 78 focused English flashcards.

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Practice VSEPR molecular geometry with 78 English flashcards for high-school and introductory-college chemistry. You should already be able to read simple formulas and Lewis structures. This is focused shape prediction and recall, not a complete chemistry course.

Cards map electron-domain counts to electron geometry; AXE notation to molecular shape and, where lone pairs change the shape, to electron geometry; and selected molecular formulas to shape. Separate prompts retrieve ideal bond-angle benchmarks. A few reverse prompts recover AXE notation from a shape plus its domain count. Contrast and error-diagnosis questions distinguish electron geometry from molecular geometry, count multiple bonds correctly, and show why a shape name alone may not determine the domain count or an exact angle.

The 13 cases are AX₂; AX₃ and AX₂E; AX₄, AX₃E, and AX₂E₂; AX₅, AX₄E, AX₃E₂, and AX₂E₃; and AX₆, AX₅E, and AX₄E₂. Later cards cover axial and equatorial sites, usual lone-pair placements, and ideal versus actual angles. The sequence starts with domains and notation, develops two-to-four-domain cases, then interleaves five- and six-domain cases before final comparisons. Related prompts are separated; the review scheduler handles longer-term spacing.

Practice is text based. Diagram identification, exhaustive Lewis-structure construction, formal charges, polarity, radicals, transition-metal coordination, seven-domain cases, hybridization, and molecular-orbital theory are excluded to keep the deck focused. Shape-to-molecule lists and every possible reverse mapping are omitted because many answers would be valid. Numerical species-angle tables are omitted: ideal benchmarks do not give exact measured angles for every molecule.

All cards carry the VSEPR tag. Original questions, answers, organization, and metadata were prepared with AI assistance and checked against university chemistry references. The cover is an original AI-generated illustration of a generic tetrahedral model; its colors do not identify elements. No source prose, diagrams, competitor cards, or examination questions were copied. Common chemical facts are not claimed as proprietary. Original material, including the generated cover to the extent applicable rights exist, is dedicated under CC0 1.0. This is independent study material, with no university, course, or examination endorsement.

Cartes de ce paquet

  1. Carte 1

    Question

    In VSEPR, what is an electron domain around a central atom?

    Réponse

    A region of electron density: one bond to a neighboring atom, regardless of bond order, or one lone pair.

  2. Carte 2

    Question

    What does the VSEPR model use to predict a central atom’s geometry?

    Réponse

    Repulsion between electron domains. The domains favor an arrangement that reduces their mutual repulsion.

  3. Carte 3

    Question

    In AXₙEₘ notation, what does A represent?

    Réponse

    The central atom whose local geometry is being described.

  4. Carte 4

    Question

    How do electron geometry and molecular geometry differ in VSEPR?

    Réponse

    Electron geometry includes all electron domains. Molecular geometry describes the arrangement of atoms around the central atom, leaving lone pairs out of the shape name.

  5. Carte 5

    Question

    How many VSEPR domains does one triple bond contribute at either bonded atom?

    Réponse

    One domain. Three shared electron pairs occupy one bonding direction.

  6. Carte 6

    Question

    In AXₙEₘ notation, what does n count?

    Réponse

    Atoms directly bonded to the central atom. A double or triple bond still contributes one X.

  7. Carte 7

    Question

    For a molecule with several central atoms, where do you apply VSEPR?

    Réponse

    At each central atom separately, using its own bonded neighbors and lone pairs.

  8. Carte 8

    Question

    In AXₙEₘ notation, what does m count?

    Réponse

    Lone pairs on the central atom. E counts pairs, not individual electrons.

  9. Carte 9

    Question

    For an AXₙEₘ center in the usual closed-shell VSEPR model, how many electron domains are present?

    Réponse

    n + m domains: bonded neighbors plus lone pairs.

  10. Carte 10

    Question

    VSEPR molecular shape of AX₂, with no lone pairs on A?

    Réponse

    Linear. The two bonded atoms lie on opposite sides of the central atom.

  11. Carte 11

    Question

    VSEPR molecular shape of AX₃, with no lone pairs on A?

    Réponse

    Trigonal planar. The central atom and three bonded atoms lie in one plane.

  12. Carte 12

    Question

    In an X–A–X bond angle, at which atom is the angle measured?

    Réponse

    At A, the central atom, between the two bonds to X atoms.

  13. Carte 13

    Question

    Does a lone pair count as one VSEPR domain or two?

    Réponse

    One domain. The pair contains two electrons, but it occupies one region around the central atom.

  14. Carte 14

    Question

    VSEPR molecular shape of AX₄, with no lone pairs on A?

    Réponse

    Tetrahedral. The four bonded atoms occupy the corners of a tetrahedron around A.

  15. Carte 15

    Question

    VSEPR molecular shape of AX₂E?

    Réponse

    Bent, also called angular or V-shaped. There are two bonded atoms and one lone pair around A.

  16. Carte 16

    Question

    What is the ideal X–A–X bond angle in AX₂ with no lone pairs?

    Réponse

    180°.

  17. Carte 17

    Question

    What electron geometry does VSEPR assign to three domains around a central atom?

    Réponse

    Trigonal planar.

  18. Carte 18

    Question

    VSEPR molecular shape of AX₃E?

    Réponse

    Trigonal pyramidal. Three bonded atoms and one lone pair occupy four electron domains.

  19. Carte 19

    Question

    What is the ideal X–A–X bond angle in tetrahedral AX₄?

    Réponse

    About 109.5°.

  20. Carte 20

    Question

    A central atom has two bonded neighbors and two lone pairs. What is its AXE notation?

    Réponse

    AX₂E₂.

  21. Carte 21

    Question

    What is the ideal X–A–X bond angle in trigonal planar AX₃?

    Réponse

    120°.

  22. Carte 22

    Question

    VSEPR molecular shape of AX₂E₂?

    Réponse

    Bent, also called angular or V-shaped. Two lone pairs occupy the other two domains.

  23. Carte 23

    Question

    What is the electron geometry around A in AX₃E?

    Réponse

    Tetrahedral: three bonding domains plus one lone-pair domain.

  24. Carte 24

    Question

    In O=C=O, how many electron domains surround carbon?

    Réponse

    Two domains. Each C=O double bond counts once.

  25. Carte 25

    Question

    What is the electron geometry around A in AX₂E?

    Réponse

    Trigonal planar: two bonding domains plus one lone-pair domain.

  26. Carte 26

    Question

    What molecular shape does VSEPR predict around carbon in CH₄?

    Réponse

    Tetrahedral. Carbon has four bonded neighbors and no lone pairs.

  27. Carte 27

    Question

    A learner counts a double bond as two VSEPR domains. What should they correct?

    Réponse

    Count it as one domain. Bond order changes the number of shared electrons, not the number of bonded directions.

  28. Carte 28

    Question

    What molecular shape does VSEPR predict around nitrogen in NH₃?

    Réponse

    Trigonal pyramidal. Nitrogen has three bonded neighbors and one lone pair.

  29. Carte 29

    Question

    What electron geometry does VSEPR assign to four domains around a central atom?

    Réponse

    Tetrahedral.

  30. Carte 30

    Question

    What molecular shape does VSEPR predict around oxygen in H₂O?

    Réponse

    Bent. Oxygen has two bonded neighbors and two lone pairs.

  31. Carte 31

    Question

    What molecular shape does VSEPR predict around carbon in the carbonate ion, CO₃²⁻?

    Réponse

    Trigonal planar. The three C–O bonding directions give three domains, even when a Lewis structure shows one double bond.

  32. Carte 32

    Question

    In the simple VSEPR model, how does a central lone pair usually affect neighboring bond angles?

    Réponse

    It tends to compress nearby bond angles because its electron density occupies more space near the central atom. This is a qualitative tendency, not a fixed number of degrees.

  33. Carte 33

    Question

    A VSEPR center is trigonal pyramidal with four total domains. What is its AXE notation?

    Réponse

    AX₃E: three bonded atoms and one lone pair.

  34. Carte 34

    Question

    Which two common AXE cases give a bent molecular shape with three or four total domains?

    Réponse

    AX₂E with three domains, and AX₂E₂ with four domains. Their electron geometries differ.

  35. Carte 35

    Question

    What electron geometry does VSEPR assign to five domains around a central atom?

    Réponse

    Trigonal bipyramidal.

  36. Carte 36

    Question

    What electron geometry does VSEPR assign to six domains around a central atom?

    Réponse

    Octahedral.

  37. Carte 37

    Question

    Does an ideal VSEPR angle give the exact measured angle in every molecule of that shape?

    Réponse

    No. It is a geometric benchmark; lone pairs and the bonding environment can change actual angles.

  38. Carte 38

    Question

    How many axial and equatorial positions are in a trigonal bipyramid?

    Réponse

    Two axial positions and three equatorial positions.

  39. Carte 39

    Question

    VSEPR molecular shape of AX₅, with no lone pairs on A?

    Réponse

    Trigonal bipyramidal.

  40. Carte 40

    Question

    VSEPR molecular shape of AX₆, with no lone pairs on A?

    Réponse

    Octahedral.

  41. Carte 41

    Question

    VSEPR molecular shape of AX₄E in the usual lowest-repulsion arrangement?

    Réponse

    Seesaw. The lone pair occupies an equatorial position in a trigonal-bipyramidal domain arrangement.

  42. Carte 42

    Question

    In an ideal trigonal bipyramid, what is the angle between two equatorial bonds?

    Réponse

    120°.

  43. Carte 43

    Question

    VSEPR molecular shape of AX₃E₂ in the usual lowest-repulsion arrangement?

    Réponse

    T-shaped. Both lone pairs occupy equatorial positions.

  44. Carte 44

    Question

    VSEPR molecular shape of AX₅E?

    Réponse

    Square pyramidal. One lone pair occupies the sixth position of an octahedral domain arrangement.

  45. Carte 45

    Question

    In an ideal trigonal bipyramid, what is the angle between an axial bond and an equatorial bond?

    Réponse

    90°.

  46. Carte 46

    Question

    VSEPR molecular shape of AX₂E₃ in the usual lowest-repulsion arrangement?

    Réponse

    Linear. Three equatorial lone pairs leave the two bonded atoms in opposite axial positions.

  47. Carte 47

    Question

    VSEPR molecular shape of AX₄E₂ in the usual lowest-repulsion arrangement?

    Réponse

    Square planar. Two opposite lone pairs leave four bonded atoms in a square around A.

  48. Carte 48

    Question

    In a trigonal-bipyramidal domain arrangement, which sites do lone pairs preferentially occupy?

    Réponse

    Equatorial sites, in the usual VSEPR arrangements with one to three lone pairs.

  49. Carte 49

    Question

    Which X–A–X angles occur in an ideal octahedral AX₆ molecule?

    Réponse

    90° between adjacent bonds and 180° between opposite bonds.

  50. Carte 50

    Question

    A VSEPR center has a seesaw shape and five total domains. What is its AXE notation?

    Réponse

    AX₄E.

  51. Carte 51

    Question

    A VSEPR center has a T-shaped molecular geometry and five total domains. What is its AXE notation?

    Réponse

    AX₃E₂.

  52. Carte 52

    Question

    In an ideal trigonal bipyramid, what is the angle between its two axial bonds?

    Réponse

    180°. The axial positions lie on opposite sides of the central atom.

  53. Carte 53

    Question

    A VSEPR center is square pyramidal with six total domains. What is its AXE notation?

    Réponse

    AX₅E.

  54. Carte 54

    Question

    In the usual octahedral AX₄E₂ arrangement, how are the two lone pairs positioned relative to each other?

    Réponse

    Opposite each other, 180° apart in the ideal domain arrangement.

  55. Carte 55

    Question

    What molecular shape does VSEPR predict for an isolated SF₄ molecule?

    Réponse

    Seesaw. Sulfur has four bonded fluorine atoms and one lone pair.

  56. Carte 56

    Question

    What molecular shape does VSEPR predict for an isolated XeF₂ molecule?

    Réponse

    Linear. Xenon has two bonded fluorine atoms and three lone pairs.

  57. Carte 57

    Question

    What is the electron geometry around A in AX₃E₂?

    Réponse

    Trigonal bipyramidal: three bonding domains plus two lone-pair domains.

  58. Carte 58

    Question

    What molecular shape does VSEPR predict for an isolated BrF₅ molecule?

    Réponse

    Square pyramidal. Bromine has five bonded fluorine atoms and one lone pair.

  59. Carte 59

    Question

    What molecular shape does VSEPR predict for an isolated XeF₄ molecule?

    Réponse

    Square planar. Xenon has four bonded fluorine atoms and two opposite lone pairs.

  60. Carte 60

    Question

    What is the electron geometry around A in AX₄E?

    Réponse

    Trigonal bipyramidal: four bonding domains plus one lone-pair domain.

  61. Carte 61

    Question

    What molecular shape does VSEPR predict for an isolated ClF₃ molecule?

    Réponse

    T-shaped. Chlorine has three bonded fluorine atoms and two equatorial lone pairs.

  62. Carte 62

    Question

    What is the electron geometry around A in AX₅E?

    Réponse

    Octahedral: five bonding domains plus one lone-pair domain.

  63. Carte 63

    Question

    What is the electron geometry around A in AX₂E₃?

    Réponse

    Trigonal bipyramidal: two bonding domains plus three lone-pair domains.

  64. Carte 64

    Question

    What molecular shape does VSEPR predict for an isolated SF₆ molecule?

    Réponse

    Octahedral. Sulfur has six bonded fluorine atoms and no lone pairs.

  65. Carte 65

    Question

    Which bond angles occur in an idealized T-shaped AX₃E₂ arrangement?

    Réponse

    90° and 180°. These are parent-geometry benchmarks; a real molecule can be distorted.

  66. Carte 66

    Question

    What is the electron geometry around A in AX₄E₂?

    Réponse

    Octahedral: four bonding domains plus two lone-pair domains.

  67. Carte 67

    Question

    Why does an octahedral VSEPR arrangement have six domains despite the name’s reference to eight?

    Réponse

    The six domains point toward the six vertices of an octahedron. Eight refers to the solid’s faces.

  68. Carte 68

    Question

    Why does a lone pair in AX₄E favor an equatorial site over an axial site?

    Réponse

    An equatorial site has two 90° interactions with other domains; an axial site has three. The equatorial choice reduces these close repulsions.

  69. Carte 69

    Question

    Which common AXE cases give a linear molecular shape with two or five total domains?

    Réponse

    AX₂ with two domains, and AX₂E₃ with five domains. A linear shape alone does not determine the electron geometry.

  70. Carte 70

    Question

    Which bond angles occur in an idealized square-pyramidal AX₅E arrangement?

    Réponse

    90° and 180°. Actual angles can deviate from these octahedral parent benchmarks.

  71. Carte 71

    Question

    A VSEPR center is square planar with six total domains. What is its AXE notation?

    Réponse

    AX₄E₂.

  72. Carte 72

    Question

    A learner assigns every bent molecule the same bond angle. What information are they missing?

    Réponse

    The electron-domain arrangement and the particular molecule. Bent includes AX₂E and AX₂E₂, and actual angles depend on the species.

  73. Carte 73

    Question

    A learner calls NH₃ tetrahedral because nitrogen has four domains. What shape distinction resolves the error?

    Réponse

    Tetrahedral is its electron geometry. Its molecular geometry is trigonal pyramidal because only the three bonded atoms define that shape.

  74. Carte 74

    Question

    Why can four bonded atoms give tetrahedral AX₄ but square planar AX₄E₂?

    Réponse

    AX₄ has four total domains. AX₄E₂ has six total domains, with two opposite lone pairs in an octahedral arrangement.

  75. Carte 75

    Question

    Which ideal parent angles are the benchmarks for an AX₄E seesaw arrangement?

    Réponse

    90°, 120°, and 180° from trigonal-bipyramidal electron geometry. Lone-pair repulsion can distort the actual bond angles.

  76. Carte 76

    Question

    What molecular shape does VSEPR predict for an isolated PF₅ molecule?

    Réponse

    Trigonal bipyramidal. Phosphorus has five bonded fluorine atoms and no lone pairs.

  77. Carte 77

    Question

    What is the electron geometry around A in AX₂E₂?

    Réponse

    Tetrahedral: two bonding domains plus two lone-pair domains.

  78. Carte 78

    Question

    Which X–A–X bond angles occur in an ideal square-planar AX₄E₂ arrangement?

    Réponse

    90° between adjacent bonds and 180° between opposite bonds.

A generic tetrahedral ball-and-stick model with an orange center and four teal neighbors against a dark blue background.

78 cartes

VSEPR Flashcards: Molecular Geometry & Bond Angles

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