Chemical Bonding

Flashcards about chemical bonding, covering ionic, covalent, and metallic bonds, electronegativity, Lewis structures, VSEPR theory, and valence bond theory.

Ionic Bond Formation

Formation of ionic bonds occurs between a metal atom and a non-metal atom. Compounds formed between elements of very different electronegativities

Covalent Bond Formation

Formation of covalent bonds occurs between two nonmetal atoms.

Metallic Bonding

Metal cations are imbedded in a sea of mobile valence electrons.

Three Types of Interactions Within a Molecule of covalent bonds

Electrons and nuclei attract one another, electrons repel each other, and nuclei repel each other.

Covalent Bond

Shared electron density

Bond Length

The separation distance at which the molecule has the maximum energetic advantage over the separated atoms. each chemical has a characteristic bond length and energy

Sigma Bond

The strongest type of covalent chemical bond, formed by the head-on overlap of atomic orbitals along the internuclear axis

Polar Covalent Bond

Unequal attractive forces lead to an unsymmetrical distribution of bonding electrons.

Electronegativity

A numerical value of how strongly an atom attracts the electrons in a chemical bond. Decreases down a Group and increases from left to right across a Period

Properties of Ionic Compounds

High melting and boiling points, brittle, and able to dissolve in water, and good conductivity when molten or dissolved(better).

Properties of Covalent Compounds

Strong forces within molecules and weak forces between them, low melting and boiling points, soft, and no conductivity of solutions. network solids

Properties of Metals

White and lustrous, conduct heat and electricity, malleable and ductile

Conventions

Each atom is represented by its elemental symbol, only valence electrons appear, lines represent shared electron pairs, and dots represent nonbonding electrons.

building lewis structures

by themselves do not imply any particular geometry for a molecule or ion,

Octet

A set of four electron pairs associated with an atom.

Lone Pairs

Nonbonding pairs of electrons.

Resonance Structures

Representations of molecules as composites of equivalent Lewis structures.

VSEPR Theory

VSEPR (valence shell electron pair repulsion), VB (valence bond)

Electronic Geometry

Geometric arrangement of electron density around central atom.

Molecular Geometry

Arrangement of atoms around central atom (i.e. does NOT include lone pairs).

Different electronic geometry

linear, trigonal planar, tetrahedral, trigonal bipyramidal, octahedral

different molecular geometry

linear, bent, trigonal pyramidal, tetrahedral, t-shaped and seesaw, square planar, square pyramidal and octahedral.

2 regions of electron density, no lone pairs

the electronic and molecular shape is linear, the angle is 180,

3 regions of electron density, no lone pairs

the electronic and molecular shape is trigonal planar, the angle is 120

4 regions of electron density, 2 lone pairs

the electronic shape is tetrahedral and molecular shape is bent, the angle is 109.5

4 regions of electron density, 1 lone pairs

the electronic shape is tetrahedral and molecular shape is trigonal pyramidal, the angle is 109.5

4 regions of electron density, 0 lone pairs

the electronic and molecular shape is tetrahedral, the angle is 109.5

5 regions of electron density, 2 lone pair

the electronic shape is trigonal bipyramidal, and molecular shape is T-shaped, the angle is 120 and 90

5 regions of electron density, 1 lone pair

the electronic shape is trigonal bipyramidal, and molecular shape is seesaw, the angle is 120 and 90

5 regions of electron density, 0 lone pair

the electronic and molecular shape is trigonal bipyramidal, the angle is 120 and 90

6 regions of electron density, 2 lone pair

the electronic shape is octahedral, and molecular shape is square planar, the angle is 90

6 regions of electron density, 1 lone pair

the electronic shape is octahedral, and molecular shape is square pyramidal, the angle is 90

6 regions of electron density, 0 lone pair

the electronic and molecular shape is octahedral, the angle is 90

Dipole Moment and equation

A covalent bond with asymmetrical distribution of electron density.

Valence Bond Theory

Electrons are either localised in bonds between two atoms or localised on a single atom.

Hybrid Orbitals

Combinations of atomic orbitals. sp is linear (and 2 groups), sp2 is trigonal planar (3 groups), sp3 is tetrahedral (4 groups)