Chem 1A Ch10

The atoms lie in a straight line.

A planar triangular molecule is one in which three atoms are located at the corners of a triangle and are bonded to a fourth atom that lies in the center of the triangle.

Four-sided geometric figure shaped like a pyramid with triangular faces.

Is one in which four atoms, located at the vertices of a tetrahedron, are bonded to a fifth atom in the center of the structure.

Consists of two triagonal pyramids (pyramids with triangular faces) that share a common base, in a trigonal bipyramid molecule, the central atom is located in the middle of triangular plane shared by the upper and lower trigonal pyramids and is bonded to five atoms that are at the vertices of the figure.

The atoms in the triangular plane are located around the equator.

The two vertical bonds pointing along the north and south axis of the sphere are 180° apart and are called axial bonds. The bond angle between an axial bond and an equatorial bond is 90°.

An eight-sided figure, which you might think of as two square pyramids sharing a common square base.

• The octahedron has only six vertices, and in an octahedral molecule we find an atom in the center of the octahedron bonded to six other atoms at the vertices.

• Valence shell electron pair repulsion model is remarkably successful at both and is also conceptually simple. The model is based on the following idea:
• Electron pairs (or groups of electron pairs) in the valence shell of an atom repel each other and will position themselves so that they are as possable, thereby minimizing the repulsions.

The term is use to describe the space occupied by a group of electrons in the valence shell of an atom.

Contains the electrons that are shared between two atoms. Therefore, all of the electrons within a given single, double, or triple bond are considered to be in the same bonding domain. A double bond (containing 4 electrons) will occupy more space than a single bond (with only 2 electrons) but all electrons shared by the atoms occupy the same general region in space, so thay all belong to the same bonding domain.

Contains valence electrons that are associated with a single atom. A nonbonding domain is either an unshared pair of valence electrons (called a lone pair) or, in some cases, a single unpaired electron (found in molecules with an odd number of valence electrons).

Linear; (180^o)

Planer triangular; (120^o)

Tetrahedral; (109.5^o) A tetrahedron is pyramid shaped. It has 4 triangular faces and 4 corners.

Trigonal bipyramid; This figure consists of two 3-sided pyramids joined by sharing a common face - the triangular plane through the center.

Octahedral; An octahedron is an 8-sided figure with 6 corners. It consists of two square pyramids that share a common square base.

• Planar triangular (ie: BF₃) [bond angle 120^o]

• V-shaped (ie: SnCl₂) [bond angle < 120^o]

• Tetrahedral (ie: CH4) [bond angle 109.5^o]

• Trigonal pyramidal (ie: NH3) [Bond angle < 109.5^o]

• Bent: (ie: H₂O) [Bond angle < 109.5^o]

• Triagonal bipyramid (ie: PCl₅) [bond angle 90^o / 120^o]

• Distorted tetrahedral or Irregular tetraghedral or Seesaw or (ie: SF₄) [bond angle > 90^o]

• T-shaped (ie: ClF₃) [bond angle < 90^o ]

• Linear (ie: I₃^-) [bond angle 180^o]

• Octahedral (ie: SF₆) all bond angles are 90^o.

• Square Pyramidal (ie: BrF₅) [bond angle >90^o ]

• Linear: 180^o (ie: HgCl₂) [bond angle 180^o ]

• Square Planar (ie: XeF₄) [bond angle 90^o ]

For a molecule containing three or more atoms, each polar bond has its own bond dipole which contributes to the overall dipole moment of the molecule. This happens because the bond dipoles have vector properties, with both direction and magnitude. In a molecule, the bond dipoles add as vectors do.

The influence of one bond dipole is canceled by the effects of the others, which causes the molecules to have net dipole moments of zero.

To be balanced.

An “unbalanced” structure.

The combination of s orbitals and p orbitals.

A bond in which the electron density is divided between two separate regions that lie on opposite sides of an imaginary line joining the two nuclei.

• 1. The basic molecular framework of a molecule is determined by the arrangment of its sigma bonds.
• 2. Hybrid orbitals are used by an atom to form its sigma bonds and to hold lone pairs of electrons.
• 3.The number of hybrid orbitals needed by an atom in a structure equals the number of atoms to which it is bonded plus the number of lone pairs of e^- in itsvalence shell.
• 4.When there is a double bond in a molecule, it consists of one sigma bond and one pi bond.
• 5.When there is a triple bond in a molecule, it consists of one sigma bond and two pi bonds.

Linear: 180^o

• Overlap one another, going towards one another. ie:

• Bond that overlap one another that are side by side. ie:
• or