Chemical Bonding and Molecular Geometry Vocabulary

50 vocabulary-style practice flashcards covering core concepts of chemical bonding, molecular geometry, VSEPR theory, nomenclature, and Lewis structures from General Chemistry CHEM1113.01.

Chemical Bond

The electrostatic forces holding atoms or ions together to form molecules and solids.

Electron Sea Model

A model for metallic bonding in which positive atomic nuclei are surrounded by a sea of delocalized electrons.

Crystal Lattice

A three-dimensional structure in an ionic solid in which every cation is surrounded by anions and vice versa.

Lattice Energy

The energy released when a solid crystal forms from separate ions in the gas state, which is always an exothermic process.

Formula Unit

The smallest, electrically neutral collection of ions that serves as the basic repeating unit of an ionic compound.

Type I Cations

Metal cations whose electrical charge is invariant across different compounds, such as alkali metals ($1+$) and alkaline earth metals ($2+$).

Type II Cations

Metal cations that can vary in electrical charge from one compound to another, typical of transition metals, inner transition metals, and p-block metals.

Ferrous

The older systematic name for the iron(II) cation, $Fe^{2+}$.

Ferric

The older systematic name for the iron(III) cation, $Fe^{3+}$.

Cuprous

The older systematic name for the copper(I) cation, $Cu^{+}$.

Cupric

The older systematic name for the copper(II) cation, $Cu^{2+}$.

Stannous

The older systematic name for the tin(II) cation, $Sn^{2+}$.

Stannic

The older systematic name for the tin(IV) cation, $Sn^{4+}$.

Plumbous

The older systematic name for the lead(II) cation, $Pb^{2+}$.

Plumbic

The older systematic name for the lead(IV) cation, $Pb^{4+}$.

Polyatomic Ion

An ion composed of a group of covalently bonded atoms carrying an overall net charge.

Oxyanion

A polyatomic anion containing oxygen covalently bonded to another element.

Hydrate

An ionic compound containing a specific number of water molecules associated with each formula unit.

Electronegativity

The quantitative ability of an atom in a chemical bond to attract bonding electrons to itself.

Pure Covalent Bond

A nonpolar covalent bond formed between two atoms with an electronegativity difference of $0$, resulting in completely equal electron sharing.

Nonpolar Covalent Bond

A covalent bond formed between two atoms with an electronegativity difference between $0.1$ and $0.4$.

Polar Covalent Bond

A covalent bond formed between two atoms with an electronegativity difference between $0.5$ and $1.9$, causing unequal electron sharing.

Ionic Bond

A chemical bond formed between atoms with an electronegativity difference greater than or equal to $2.0$, characterized by electron transfer.

Space-Filling Model

A 3-D molecular model in which atoms fill the space between each other to represent best estimates of scaled physical appearance.

Hydrocarbon

An organic compound composed entirely of carbon and hydrogen atoms.

Organic Compound

A molecular compound containing carbon combined with other elements such as hydrogen, oxygen, and nitrogen.

Monomer

A small individual molecule that can link together repeatedly with others to form a polymer.

Polymer

A very large molecule composed of many smaller repeating units (monomers) linked together covalently.

Lewis Bonding Theory

A chemical bonding theory emphasizing valence electrons to explain bonding, molecular stability, shape, size, and polarity.

Lewis Structure

A structural diagram representing a molecule or ion where valence electrons are depicted as dots and bonding electron pairs as lines or dot pairs.

Resonance Structures

Two or more valid Lewis structures drawn for a single molecule or ion when one structure alone cannot accurately model the bonding.

Formal Charge

An electron bookkeeping value calculated as $\text{FC} = (\text{valence } e^-) - (\text{nonbonding } e^-) - \frac{1}{2}(\text{bonding } e^-)$.

Bond Energy

The amount of energy required, in the gas state, to break one mole of a specific chemical bond in a compound.

Bond Length

The distance between the nuclei of two bonded atoms at their equilibrium position.

VSEPR Theory

Valence Shell Electron Pair Repulsion theory, which states that electron groups around a central atom position themselves as far apart as possible to minimize repulsions.

Electron Group

A set of valence electrons located around a central atom, defined as a lone pair, a single bond, a double bond, a triple bond, or a single electron.

Linear Geometry

A molecular or electron geometry in which two electron groups around a central atom are arranged $180^\times$ apart.

Trigonal Planar Geometry

A molecular or electron geometry in which three electron groups around a central atom lie in one plane with bond angles of $120^\times$.

Bent Geometry

A non-linear molecular geometry resulting when lone pairs exert extra repulsion and compress bond angles away from idealized geometries.

Tetrahedral Geometry

A molecular or electron geometry in which four electron groups around a central atom are oriented toward the corners of a tetrahedron with bond angles of $109.5^\times$.

Trigonal Pyramidal Geometry

A molecular geometry formed when a central atom has four electron groups consisting of three bonding groups and one lone pair, yielding bond angles $<109.5^\times$.

Trigonal Bipyramidal Geometry

A geometry with five electron groups around a central atom, featuring $120^\times$ equatorial bond angles and $90^\times$ axial bond angles.

Seesaw Geometry

A molecular geometry formed when a central atom has five electron groups consisting of four bonding groups and one lone pair.

T-Shaped Geometry

A molecular geometry formed when a central atom has five electron groups consisting of three bonding groups and two lone pairs.

Octahedral Geometry

A geometry with six electron groups arranged symmetrically around a central atom with $90^\times$ bond angles.

Square Pyramidal Geometry

A molecular geometry formed when a central atom has six electron groups consisting of five bonding groups and one lone pair.

Square Planar Geometry

A molecular geometry formed when a central atom has six electron groups consisting of four bonding groups and two lone pairs.

Dipole Moment

A quantitative measure of net molecular polarity that occurs when there is a spatial separation of positive and negative partial charges.

Percent Ionic Character

The percentage ratio of a bond's actual dipole moment to what it would be if the electron were completely transferred, increasing as electronegativity difference increases.

Cobalt(II) chloride hexahydrate

A hydrated ionic compound represented by the chemical formula $CoCl_2 \times 6H_2O$.