VSEPR Flashcards: Molecular Geometry & Bond Angles
Practice VSEPR shapes, electron geometry, lone pairs, AXE notation, and ideal bond angles with 78 focused English flashcards.
About this deck
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.
Cards in this deck
Card 1
Question
In VSEPR, what is an electron domain around a central atom?
Answer
A region of electron density: one bond to a neighboring atom, regardless of bond order, or one lone pair.
Card 2
Question
What does the VSEPR model use to predict a central atom’s geometry?
Answer
Repulsion between electron domains. The domains favor an arrangement that reduces their mutual repulsion.
Card 3
Question
In AXₙEₘ notation, what does A represent?
Answer
The central atom whose local geometry is being described.
Card 4
Question
How do electron geometry and molecular geometry differ in VSEPR?
Answer
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.
Card 5
Question
How many VSEPR domains does one triple bond contribute at either bonded atom?
Answer
One domain. Three shared electron pairs occupy one bonding direction.
Card 6
Question
In AXₙEₘ notation, what does n count?
Answer
Atoms directly bonded to the central atom. A double or triple bond still contributes one X.
Card 7
Question
For a molecule with several central atoms, where do you apply VSEPR?
Answer
At each central atom separately, using its own bonded neighbors and lone pairs.
Card 8
Question
In AXₙEₘ notation, what does m count?
Answer
Lone pairs on the central atom. E counts pairs, not individual electrons.
Card 9
Question
For an AXₙEₘ center in the usual closed-shell VSEPR model, how many electron domains are present?
Answer
n + m domains: bonded neighbors plus lone pairs.
Card 10
Question
VSEPR molecular shape of AX₂, with no lone pairs on A?
Answer
Linear. The two bonded atoms lie on opposite sides of the central atom.
Card 11
Question
VSEPR molecular shape of AX₃, with no lone pairs on A?
Answer
Trigonal planar. The central atom and three bonded atoms lie in one plane.
Card 12
Question
In an X–A–X bond angle, at which atom is the angle measured?
Answer
At A, the central atom, between the two bonds to X atoms.
Card 13
Question
Does a lone pair count as one VSEPR domain or two?
Answer
One domain. The pair contains two electrons, but it occupies one region around the central atom.
Card 14
Question
VSEPR molecular shape of AX₄, with no lone pairs on A?
Answer
Tetrahedral. The four bonded atoms occupy the corners of a tetrahedron around A.
Card 15
Question
VSEPR molecular shape of AX₂E?
Answer
Bent, also called angular or V-shaped. There are two bonded atoms and one lone pair around A.
Card 16
Question
What is the ideal X–A–X bond angle in AX₂ with no lone pairs?
Answer
180°.
Card 17
Question
What electron geometry does VSEPR assign to three domains around a central atom?
Answer
Trigonal planar.
Card 18
Question
VSEPR molecular shape of AX₃E?
Answer
Trigonal pyramidal. Three bonded atoms and one lone pair occupy four electron domains.
Card 19
Question
What is the ideal X–A–X bond angle in tetrahedral AX₄?
Answer
About 109.5°.
Card 20
Question
A central atom has two bonded neighbors and two lone pairs. What is its AXE notation?
Answer
AX₂E₂.
Card 21
Question
What is the ideal X–A–X bond angle in trigonal planar AX₃?
Answer
120°.
Card 22
Question
VSEPR molecular shape of AX₂E₂?
Answer
Bent, also called angular or V-shaped. Two lone pairs occupy the other two domains.
Card 23
Question
What is the electron geometry around A in AX₃E?
Answer
Tetrahedral: three bonding domains plus one lone-pair domain.
Card 24
Question
In O=C=O, how many electron domains surround carbon?
Answer
Two domains. Each C=O double bond counts once.
Card 25
Question
What is the electron geometry around A in AX₂E?
Answer
Trigonal planar: two bonding domains plus one lone-pair domain.
Card 26
Question
What molecular shape does VSEPR predict around carbon in CH₄?
Answer
Tetrahedral. Carbon has four bonded neighbors and no lone pairs.
Card 27
Question
A learner counts a double bond as two VSEPR domains. What should they correct?
Answer
Count it as one domain. Bond order changes the number of shared electrons, not the number of bonded directions.
Card 28
Question
What molecular shape does VSEPR predict around nitrogen in NH₃?
Answer
Trigonal pyramidal. Nitrogen has three bonded neighbors and one lone pair.
Card 29
Question
What electron geometry does VSEPR assign to four domains around a central atom?
Answer
Tetrahedral.
Card 30
Question
What molecular shape does VSEPR predict around oxygen in H₂O?
Answer
Bent. Oxygen has two bonded neighbors and two lone pairs.
Card 31
Question
What molecular shape does VSEPR predict around carbon in the carbonate ion, CO₃²⁻?
Answer
Trigonal planar. The three C–O bonding directions give three domains, even when a Lewis structure shows one double bond.
Card 32
Question
In the simple VSEPR model, how does a central lone pair usually affect neighboring bond angles?
Answer
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.
Card 33
Question
A VSEPR center is trigonal pyramidal with four total domains. What is its AXE notation?
Answer
AX₃E: three bonded atoms and one lone pair.
Card 34
Question
Which two common AXE cases give a bent molecular shape with three or four total domains?
Answer
AX₂E with three domains, and AX₂E₂ with four domains. Their electron geometries differ.
Card 35
Question
What electron geometry does VSEPR assign to five domains around a central atom?
Answer
Trigonal bipyramidal.
Card 36
Question
What electron geometry does VSEPR assign to six domains around a central atom?
Answer
Octahedral.
Card 37
Question
Does an ideal VSEPR angle give the exact measured angle in every molecule of that shape?
Answer
No. It is a geometric benchmark; lone pairs and the bonding environment can change actual angles.
Card 38
Question
How many axial and equatorial positions are in a trigonal bipyramid?
Answer
Two axial positions and three equatorial positions.
Card 39
Question
VSEPR molecular shape of AX₅, with no lone pairs on A?
Answer
Trigonal bipyramidal.
Card 40
Question
VSEPR molecular shape of AX₆, with no lone pairs on A?
Answer
Octahedral.
Card 41
Question
VSEPR molecular shape of AX₄E in the usual lowest-repulsion arrangement?
Answer
Seesaw. The lone pair occupies an equatorial position in a trigonal-bipyramidal domain arrangement.
Card 42
Question
In an ideal trigonal bipyramid, what is the angle between two equatorial bonds?
Answer
120°.
Card 43
Question
VSEPR molecular shape of AX₃E₂ in the usual lowest-repulsion arrangement?
Answer
T-shaped. Both lone pairs occupy equatorial positions.
Card 44
Question
VSEPR molecular shape of AX₅E?
Answer
Square pyramidal. One lone pair occupies the sixth position of an octahedral domain arrangement.
Card 45
Question
In an ideal trigonal bipyramid, what is the angle between an axial bond and an equatorial bond?
Answer
90°.
Card 46
Question
VSEPR molecular shape of AX₂E₃ in the usual lowest-repulsion arrangement?
Answer
Linear. Three equatorial lone pairs leave the two bonded atoms in opposite axial positions.
Card 47
Question
VSEPR molecular shape of AX₄E₂ in the usual lowest-repulsion arrangement?
Answer
Square planar. Two opposite lone pairs leave four bonded atoms in a square around A.
Card 48
Question
In a trigonal-bipyramidal domain arrangement, which sites do lone pairs preferentially occupy?
Answer
Equatorial sites, in the usual VSEPR arrangements with one to three lone pairs.
Card 49
Question
Which X–A–X angles occur in an ideal octahedral AX₆ molecule?
Answer
90° between adjacent bonds and 180° between opposite bonds.
Card 50
Question
A VSEPR center has a seesaw shape and five total domains. What is its AXE notation?
Answer
AX₄E.
Card 51
Question
A VSEPR center has a T-shaped molecular geometry and five total domains. What is its AXE notation?
Answer
AX₃E₂.
Card 52
Question
In an ideal trigonal bipyramid, what is the angle between its two axial bonds?
Answer
180°. The axial positions lie on opposite sides of the central atom.
Card 53
Question
A VSEPR center is square pyramidal with six total domains. What is its AXE notation?
Answer
AX₅E.
Card 54
Question
In the usual octahedral AX₄E₂ arrangement, how are the two lone pairs positioned relative to each other?
Answer
Opposite each other, 180° apart in the ideal domain arrangement.
Card 55
Question
What molecular shape does VSEPR predict for an isolated SF₄ molecule?
Answer
Seesaw. Sulfur has four bonded fluorine atoms and one lone pair.
Card 56
Question
What molecular shape does VSEPR predict for an isolated XeF₂ molecule?
Answer
Linear. Xenon has two bonded fluorine atoms and three lone pairs.
Card 57
Question
What is the electron geometry around A in AX₃E₂?
Answer
Trigonal bipyramidal: three bonding domains plus two lone-pair domains.
Card 58
Question
What molecular shape does VSEPR predict for an isolated BrF₅ molecule?
Answer
Square pyramidal. Bromine has five bonded fluorine atoms and one lone pair.
Card 59
Question
What molecular shape does VSEPR predict for an isolated XeF₄ molecule?
Answer
Square planar. Xenon has four bonded fluorine atoms and two opposite lone pairs.
Card 60
Question
What is the electron geometry around A in AX₄E?
Answer
Trigonal bipyramidal: four bonding domains plus one lone-pair domain.
Card 61
Question
What molecular shape does VSEPR predict for an isolated ClF₃ molecule?
Answer
T-shaped. Chlorine has three bonded fluorine atoms and two equatorial lone pairs.
Card 62
Question
What is the electron geometry around A in AX₅E?
Answer
Octahedral: five bonding domains plus one lone-pair domain.
Card 63
Question
What is the electron geometry around A in AX₂E₃?
Answer
Trigonal bipyramidal: two bonding domains plus three lone-pair domains.
Card 64
Question
What molecular shape does VSEPR predict for an isolated SF₆ molecule?
Answer
Octahedral. Sulfur has six bonded fluorine atoms and no lone pairs.
Card 65
Question
Which bond angles occur in an idealized T-shaped AX₃E₂ arrangement?
Answer
90° and 180°. These are parent-geometry benchmarks; a real molecule can be distorted.
Card 66
Question
What is the electron geometry around A in AX₄E₂?
Answer
Octahedral: four bonding domains plus two lone-pair domains.
Card 67
Question
Why does an octahedral VSEPR arrangement have six domains despite the name’s reference to eight?
Answer
The six domains point toward the six vertices of an octahedron. Eight refers to the solid’s faces.
Card 68
Question
Why does a lone pair in AX₄E favor an equatorial site over an axial site?
Answer
An equatorial site has two 90° interactions with other domains; an axial site has three. The equatorial choice reduces these close repulsions.
Card 69
Question
Which common AXE cases give a linear molecular shape with two or five total domains?
Answer
AX₂ with two domains, and AX₂E₃ with five domains. A linear shape alone does not determine the electron geometry.
Card 70
Question
Which bond angles occur in an idealized square-pyramidal AX₅E arrangement?
Answer
90° and 180°. Actual angles can deviate from these octahedral parent benchmarks.
Card 71
Question
A VSEPR center is square planar with six total domains. What is its AXE notation?
Answer
AX₄E₂.
Card 72
Question
A learner assigns every bent molecule the same bond angle. What information are they missing?
Answer
The electron-domain arrangement and the particular molecule. Bent includes AX₂E and AX₂E₂, and actual angles depend on the species.
Card 73
Question
A learner calls NH₃ tetrahedral because nitrogen has four domains. What shape distinction resolves the error?
Answer
Tetrahedral is its electron geometry. Its molecular geometry is trigonal pyramidal because only the three bonded atoms define that shape.
Card 74
Question
Why can four bonded atoms give tetrahedral AX₄ but square planar AX₄E₂?
Answer
AX₄ has four total domains. AX₄E₂ has six total domains, with two opposite lone pairs in an octahedral arrangement.
Card 75
Question
Which ideal parent angles are the benchmarks for an AX₄E seesaw arrangement?
Answer
90°, 120°, and 180° from trigonal-bipyramidal electron geometry. Lone-pair repulsion can distort the actual bond angles.
Card 76
Question
What molecular shape does VSEPR predict for an isolated PF₅ molecule?
Answer
Trigonal bipyramidal. Phosphorus has five bonded fluorine atoms and no lone pairs.
Card 77
Question
What is the electron geometry around A in AX₂E₂?
Answer
Tetrahedral: two bonding domains plus two lone-pair domains.
Card 78
Question
Which X–A–X bond angles occur in an ideal square-planar AX₄E₂ arrangement?
Answer
90° between adjacent bonds and 180° between opposite bonds.
78 cards
VSEPR Flashcards: Molecular Geometry & Bond Angles
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