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