Organic Chemistry Chapter 1 - Structure and Bonding Vocabulary

Practice vocabulary flashcards covering electronic structure, bonding types, formal charges, resonance, structural formulas, hybridization, and isomerism based on Chapter 1.

Organic Chemistry

The study of carbon compounds, covering their structure, properties, reactivity, and synthesis.

Isotopes

Atoms of the same element that have the same number of protons but different numbers of neutrons (such as ${}^{12}\text{C}$, ${}^{13}\text{C}$, and ${}^{14}\text{C}$).

Valence Electrons

Electrons in the outermost shell of an atom that determine its chemical reactivity and participate in bond breaking and formation.

Aufbau Principle

An electronic configuration rule stating that electrons fill the lowest energy atomic orbitals first.

Pauli Exclusion Principle

A principle stating that a maximum of two spin-paired electrons can occupy a single atomic orbital.

Hund's Rule

A rule stating that when electrons occupy degenerate orbitals of equal energy, they enter separate orbitals individually before pairing up.

Octet Rule

The principle that atoms tend to transfer or share electrons to attain a full valence shell of eight electrons, achieving a stable noble gas configuration.

Dipole Moment ($\mu$)

A quantitative measure of electrical charge separation defined by the equation $\mu = \delta \times d$, where $\delta$ is the partial charge and $d$ is the bond length.

Formal Charge

The charge assigned to an atom in a molecule, calculated as $\text{FC} = [\text{group number}] - [\text{nonbonding electrons}] - \frac{1}{2}[\text{shared electrons}]$.

Resonance Forms

Multiple Lewis structures for a single molecule that differ only in the arrangement of delocalized electrons, while the connectivity of the atoms remains identical.

Major Contributor

The most stable resonance form of a structure, characterized by complete octets on all atoms, the maximum number of bonds, minimal charge separation, and negative formal charge on the most electronegative atom.

Four Types of Structural Arrows

Arrows used in drawing organic structures and reactions: reaction arrows, equilibrium arrows, resonance arrows, and green curved arrows.

Condensed Structural Formula

A structural representation written without showing all individual bonds, where atoms bonded to a central atom are listed immediately following it.

Line-Angle Formula

A skeletal drawing method where bonds are shown as lines, carbon atoms exist at vertices and endpoints, hydrogens bonded to carbon are omitted, and heteroatoms are explicitly shown.

Empirical Formula

The simplest whole-number ratio of the elements present in a chemical compound.

Node

A region or plane in an orbital where the wave function amplitude ($\psi$) and the electron density ($\psi^2$) are equal to zero.

Sigma ($\sigma$) Bond

A strong covalent bond formed by the head-on or cylindrical overlap of orbitals along the internuclear axis.

Pi ($\pi$) Bond

A covalent bond formed by the sideways overlap of parallel $p$ orbitals, concentrating electron density above and below the internuclear axis.

VSEPR Theory

Valence-Shell Electron-Pair Repulsion theory, which predicts molecular geometry based on minimizing repulsion between electron pairs surrounding a central atom.

$sp$ Hybrid Orbitals

Hybrid orbitals formed by mixing one $s$ orbital and one $p$ orbital, resulting in a linear geometry with bond angles of $180^\circ$.

$sp^2$ Hybrid Orbitals

Hybrid orbitals formed by mixing one $s$ orbital and two $p$ orbitals, resulting in a trigonal planar geometry with bond angles of $120^\circ$.

$sp^3$ Hybrid Orbitals

Hybrid orbitals formed by mixing one $s$ orbital and three $p$ orbitals, resulting in a tetrahedral geometry with bond angles of $109.5^\circ$.

Constitutional Isomers

Isomers that have the same molecular formula but differ in their bonding sequence (atom connectivity).

Stereoisomers

Isomers that have the same molecular formula and identical atom connectivity, but differ in the three-dimensional spatial arrangement of their atoms.

Cis-Trans Isomers

Geometric stereoisomers resulting from restricted rotation around a double bond, where substituents point to either the same side (cis) or opposite sides (trans).