Chem 111 Chp 9

Electrons that occupy antibonding molecular orbitals

A molecular orbital that denies electron density to the space between nuclei and destabilizes a molecule when occupied by electrons.

Covalent bonds oriented parallel to the vertical axis in a trigonal bipyramidal molecule.

A molecule that is nonlinear.

The angle formed by two bonds that extend from the same atom.

A dipole within a molecule associated with a specific bond.

A region between two atoms that contains one or more electron pairs in bonds and that influences molecular shape.

A molecular orbital that introduces a buildup of electron density between nuclei and stabilizes a molecule when occupied by electrons.

A particular relative orientation or geometric form of a flexible molecule.

The difference between the energy a substance would have if its molecules had no delocalized molecular orbitals and the energy it has because of such orbitals.

A molecular orbital that spreads over more than two nuclei.

Lacking or deficient in symmetry. In a dissymmetric molecule the effects of the individual bond dipoles do not cancel, causing the molecule as a whole to be polar.

A description of a molecule in which the central atom is surrounded by five electron pairs, one of which is a lone pair of electrons. The central atom is bonded to four other atoms. The structure is also said to have a seesaw shape.

A region around an atom where one or more electron pairs are concentrated and which influences the shape of a molecule.

A covalent bond located in the plane perpendicular to the long axis of a trigonal bipyramidal molecule.

A molecule in which not all atoms are of the same element.

A diatomic molecule in which both atoms are of the same element.

Orbitals formed by mixing two or more of the basic atomic orbitals of an atom and that make possible more effective overlaps with the orbitals of adjacent atoms than do ordinary atomic orbitals.

A molecule all of whose atoms lie on a straight line.

A pair of electrons in the valence shell of an atom that is not shared with another atom. An unshared pair of electrons.

A theory about covalent bonds that views a molecule as a collection of positive nuclei surrounded by electrons distributed among a set of bonding, antibonding, and nonbonding orbitals of different energies.

An orbital that extends over two or more atomic nuclei.

A region in the valence shell of an atom that holds an unshared pair of electrons and that influences the shape of a molecule.

A molecular orbital that has no net effect on the stability of a molecule when populated with electrons and that is localized on one atom in the molecule.

A molecule in which the atoms do not lie in a straight line.

A molecule in which a central atom is surrounded by six atoms located at the vertices of an imaginary octahedron.

An eight-sided figure that can be envisioned as two square pyramids sharing the common square base.

A portion of two orbitals from different atoms that share the same space in a molecule.

• A bond formed by the sideways overlap of a pair of p
• orbitals and that concentrates electron density into two separate regions that lie on opposite sides of a plane that contains an imaginary line joining the nuclei.

A molecule in which a central atom holds three other atoms located at the corners of an equilateral triangle and that includes the central atom at its center.

A description given to a molecule in which the central atom has five electron pairs in its valence shell, one of which is a lone pair and the others are used in bonds to other atoms

A bond formed by the head-to-head overlap of two atomic orbitals and in which electron density becomes concentrated along and around the imaginary line joining the two nuclei.

A molecule with a central atom having four bonds that point to the corners of a square.

A pyramid with four triangular sides and a square base.

An object is symmetric if it looks the same when rotated, reflected in a mirror, or reflected through a point.

A molecule having five electron domains in its valence shell, two of which contain lone pairs. The other three are used in bonds to other atoms. The molecule has the shape of the letter T, with the central atom located at the intersection of the two crossing lines

A molecule with a central atom bonded to four other atoms located at the corners of an imaginary tetrahedron.

A four-sided figure with four triangular faces and shaped like a pyramid.

A six-sided figure made of two three-sided pyramids that share a common face

A molecule with a central atom holding five other atoms that are located at the corners of a trigonal bipyramid.

A molecule that consists of an atom, situated at the top of a three-sided pyramid, that is bonded to three other atoms located at the corners of the base of the pyramid.

A theory of covalent bonding that views a bond as being formed by the sharing of one pair of electrons between two overlapping atomic or hybrid orbitals.

• valence shell electron pair repulsion model:
• The bonding and nonbonding (lone pair) electron domains in the valence shell of an atom seek an arrangement that leads to minimum repulsions
• and thereby determine the geometry of a molecule.

• Linear
• 180*
• sp hybrid

• Planar Triangle
• 120*
• sp²

• Tetrahedral
• 109.5*
• sp³ hybrid orbital

• Trigonal Pyramidal
• 107*
• sp³ hybrid orbital

• Non-Linear Bent
• 104.5*
• sp³ hybrid orbital

• Trigonal Bipyramidal
• 120*, 90*
• sp³d hybrid orbital

• Octahedral
• 90*
• sp³d² hybrid orbital

• Square Planar
• 90*
• sp³d²