Lecture 9 - Lewis Structures II

Wednesday, January 31, 2024

10:31 PM

"The nature of the chemical bond is the problem at the heart of all chemistry." - ﷟HYPERLINK "https://www.nobelprize.org/prizes/chemistry/1954/ceremony-speech/"Linus Pauling Class notes can now be found in an alternative location: https://bricejurban.github.io/CHEM101/ Assignments due this week: ﷟HYPERLINK "https://boisestatecanvas.instructure.com/courses/28698/modules/items/2975632"HW 5 - Inorganic Nomenclature Part 1 (Aktiv Chemistry) (due tomorrow Fri 2/9) ﷟HYPERLINK "https://boisestatecanvas.instructure.com/courses/28698/modules/items/2975633"HW 6 - Lewis Structures, Polarity (Aktiv Chemistry) (Sun 2/11) Assignments due next week: ﷟HYPERLINK "https://boisestatecanvas.instructure.com/courses/28698/modules/items/2975637"HW 7 - Inorganic Nomenclature Part 2 (Aktiv Chemistry) (Wed 2/14) ﷟HYPERLINK "https://boisestatecanvas.instructure.com/courses/28698/modules/items/2975638"HW 8 - Resonance, VSEPR, IMFs (Fri 2/16) Office Hours: Friday 11-1 CIC ﷟HYPERLINK "https://calendly.com/bricejurban/office-hours"By appointment Today's Schedule: Thursday (2/8) Lewis Structures Not enough electrons Too many electrons Resonance Structures Looking Ahead Tuesday (2/13) Schedule VSEPR Molecular Polarity Intermolecular Forces Application to DNA Thursday (2/15) Schedule Chemical Reactions and Types Balancing Equations Drawing Covalent Molecular Structures (Lewis Structures) Algorithm for Drawing Lewis Structures Arrange the symbols of the atoms that are bonded together in the molecule next to one another. Compute the total number of valence electrons in the molecule by adding the number of valence electrons for all the atoms in the molecule. If the species is an ion rather than a molecule, then you must take the charge of the ion into account by adding electrons if it is a negative ion or subtracting electrons if it is a positive ion Represent a two-electron covalent bond by placing a line between the atoms that are assumed to be bonded to each other Arrange the remaining valence electrons as lone pairs about each atom so that the octet rule is satisfied for each one Tips: The central atom is usually the least electronegative unless hydrogen which is always terminal. Some compounds will not have a central atom, but several. Be, B, and Al have deficient octets Elements in the 3rd row (S, P . . . )can expand their octet to have 10, 12, or more e-. If the molecule is an ion, bracket the structure and put a charge in the corner Molecules with an odd number of electrons will form a free radical, a reactive species.
that the octet rule is satisfied for each one Check the formal charge on each atom to help with competing structures If there is not enough electrons, you may need to use double bonds, triple bonds or rings or the central atom(s) has a deficient octet or you have a radical If there are too many electrons, you may need to put electron pairs on the central atom and/or form double bonds to reduce formal charges (this will not be assessed in CHEM 101) Draw any valid resonance structures if requested Molecules with an odd number of electrons will form a free radical, a reactive species. Assigning Formal Charges help with determining the best structure (Step 5) Sometimes more than one possible structure may be possible. In that case it is necessary to assign a formal charge to the atoms in the structure to help aid us in choosing the correct one. We assume each pair of shared electrons are shared equally and assign one of the electrons to each atom. Lone electron pairs are assigned to the atom they are located on. Use this equation: Untitled picture.png Machine generated alternative text: formal charge on an atom In a Lewis formula total number of — valence electrons — in the free atom total number of lone-pair electrons total number of bonds Which structure is preferable for hydroxylamine? NH3O NH2OH Which structure is preferable for hydrogen peroxide? Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings
H2OO HOOH When there are not enough electrons (Step 6) Some elements are electron deficient are do not require an octet when forming a covalent bond. This is restricted to H, Li, Mg, Be, B, and Al. What is more likely is that you need to use double or triple bonds, especially if there is C or O present. If the molecule is larger, you can also form ring structures to use up 2 electrons. Lastly, if you have an odd number of electrons radical (unpaired electron) compounds are also possible. H2 Li2 BeCl2 MgH2 BH3 AlBr3 Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings
C2H6 (ethane) C2H4 (ethene) C2H2 (ethyne) C6H6 (benzene) C2H3O2– (acetate) CH3• (methyl radical) (C6H5)3C• Trityl radical Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings
(methyl radical) O2•– (superoxide anion radical) Trityl radical First organic radical discovered. Moses Gomberg in 1900 at University of Michigan (my alma mater) When there are too many electrons (Step 7) Some elements allow for an expanded octet when forming covalent bonds. This is restricted to elements in the third shell or higher including the elements: P, S, Cl, As, Se, Te, Br, I, and even Xe. Never will an element such as C, N, O, or F have an expanded octet I will not test on this (unless it is an extra credit problem)  SF6             XeF2 IF5 Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings 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  When resonance structures are needed (Step 8) Resonance refers to areas in the molecule where the electrons in double/triple bonds are delocalized across more than two atoms. Especially for polyatomic ions and organic molecules, multiple structures can be needed to fully capture the molecule's complexity. A double headed arrow is used to indicate a resonance structure ↔. Molecules do not transition between resonance structures but exist as them all simultaneously. They are the closest approximation we can get to representing the molecule. HCO3– (hydrogen carbonate)           C2O42– (oxalate) Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink 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  Bond lengths and strengths When more electrons are shared between atoms, there is increased orbital overlap between the atoms. Therefore, double bonds have more overlap than single covalent bonds and thus are shorter and stronger. Furthermore, triple bonds have even more overlap than double bonds and are the shortest and strongest bonds. Here's a simple comparison of common bond lengths and their corresponding energies Bond Bond Length (Å) Bond Energy (kJ/mol) C–C 1.54 345 C=C 1.34 611 C≡C 1.20 837 C–N 1.43 290 C=N 1.38 615 C≡N 1.16 891 C–O 1.43 350 C=O 1.23 741 C≡O 1.13 1080 Molecules exist in three-dimensions dictated by electronic repulsion Valence-Shell Electron Pair Repulsion (VSEPR) Theory VSEPR theory is used to predict the shape of molecules based on the idea that electron pairs around a central atom will arrange themselves as far apart as possible to minimize repulsion. Consider both bonding (shared between atoms) and lone (non-bonding) pairs of electrons in the valence shell of the central atom. The geometric arrangement of the electron pairs determines the shape of the molecule. Lone pair-lone pair > Lone pair-bonding pair > Bonding pair-bonding pair. This means lone pairs repel more strongly than bonding pairs. Presence of lone pairs can alter the ideal bond angle and shape due to their greater repulsion. For example, NH₃ is trigonal pyramidal, not planar. To predict a molecule's shape, draw its Lewis structure, determine the number of electron pairs, arrange them to minimize repulsion, and deduce the molecular geometry. Molecular Geometry Bonding Pairs Lone Pairs Total Electron Pairs Bond Angle(s) Example Molecules Linear 2 0 2 180° CO₂, BeCl₂ Trigonal Planar 3 0 3 120° BF₃, AlCl₃ Tetrahedral 4 0 4 109.5° CH₄, SiCl₄ Trigonal Pyramidal 3 1 4 <109.5° NH₃, PCl₃ Bent (V-shaped) 2 2 4 <109.5° H₂O, H₂S Trigonal Bipyramidal 5 0 5 120°, 90° PCl₅, PF₅ See-Saw 4 1 5 <120°, <90° SF₄, SeCl₄ Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings
See-Saw 4 1 5 <120°, <90° SF₄, SeCl₄ T-shaped 3 2 5 <90° ClF₃, BrF₃ Linear 2 3 5 180° XeF₂, I₃⁻ Octahedral 6 0 6 90° SF₆, SeF₆ Square Pyramidal 5 1 6 <90° BrF₅, IF₅ Square Planar 4 2 6 90° XeF₄, PtCl₄²⁻ BeCl2 BCl3 SF2 SO3 SiH4 PCl5 BrF3 I3– SeF4
IF5 O3 PH3

 

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