Chemical Bonding, Stereochemistry, and Intermolecular Forces

Comprehensive vocabulary flashcards covering chemical bonding types, Lewis structures, periodic trends, VSEPR molecular geometry, intermolecular forces, and solid state structures.

Chemical Bond

An electrostatic attraction between two atoms resulting from the partial or complete transfer of electrons or the sharing of electrons to fill their valence level and achieve a more stable, lower energy state.

Octet Rule

The principle that atoms lose, gain, or share electrons in order to achieve a filled valence level of eight electrons (with hydrogen being an exception that fills with two electrons).

Lone Pairs

Pairs of valence electrons that stabilize each other without participating in bonding.

Bonding Electrons

Unpaired valence electrons that need to form a bond with other atoms to become stable.

Ionic Bond

The electrostatic attraction between oppositely charged ions formed through the complete transfer of electrons from a metal atom to a non-metal atom.

Crystal Lattice

A three-dimensional repeating pattern of alternating positive and negative ions held together by electrostatic attractions in an ionic compound.

Formula Unit

The smallest whole-number ratio of positive and negative ions within an ionic crystal lattice (such as $1:1$ for $NaCl(s)$ or $1:2$ for $CaF_2(s)$).

Covalent Bond

An electrostatic attraction between the positively charged nuclei of two non-metal atoms and a pair of shared bonding electrons.

Single Bond

A covalent bond where one pair of electrons is shared between two atoms so each atom fills its valence shell.

Double Bond

A covalent bond where two pairs of electrons are shared between two atoms so each atom fills its valence shell.

Triple Bond

A covalent bond where three pairs of electrons are shared between two atoms so each atom fills its valence shell.

Central Atom

The atom in a molecule that possesses the highest number of bonding electrons and to which the other surrounding atoms attach.

Metallic Bonding

The electrostatic attraction between positive metal nuclei and a surrounding "sea" of freely moving, shared valence electrons.

Delocalized Electrons

Electrons in metallic bonding that are released by metal atoms and are free to move throughout the structure.

Atomic Radius

A periodic property representing atom size that increases down a group due to greater inner electron shielding and decreases across a period due to increased nuclear pull with no shielding increase.

Electronegativity

The tendency of an atom to attract the shared electrons of a chemical bond toward its own nucleus.

Bond Dipole

A representation of charge separation in a polar bond, illustrated as an arrow pointing from the positive pole (less electronegative atom) to the negative pole (more electronegative atom).

Non-Polar Covalent Bond

A covalent bond characterized by the equal sharing of bonding electrons, resulting in no partial charges on either atom.

Polar Covalent Bond

A covalent bond characterized by the unequal sharing of bonding electrons due to an electronegativity difference, producing partial positive ($\delta+$) and partial negative ($\delta-$) charges.

Stereochemistry

The study of the relative spatial arrangement of atoms that form the structure of molecules and their manipulation.

VSEPR Theory

Valence-Shell Electron Pair Repulsion Theory; a model stating that electron pairs (bonds and lone pairs) around a central atom adjust their positions to stay as far apart as possible to minimize electrostatic repulsion.

Hypervalent Molecule

A molecule in which the central atom exceeds the octet rule by accommodating more than eight electrons around it (such as sulfur in $SF_6$).

Intramolecular Bonds

Strong chemical forces (ionic, covalent, or metallic) that bind atoms or ions together within a molecule or crystal lattice, requiring large amounts of energy to break.

Intermolecular Bonds

Forces of attraction that form between separate covalent molecules, which are much weaker than intramolecular bonds and are broken during physical changes such as melting or boiling.

London Dispersion Forces (LDF)

The weakest intermolecular force, caused by attractions between momentary instantaneous dipoles and induced dipoles in neighbouring molecules.

Dipole-Dipole Attraction

An intermolecular force occurring in polar molecules where the permanent partial positive end of one molecule is electrostatically attracted to the partial negative end of another molecule.

Hydrogen Bonding

An exceptionally strong type of dipole-dipole attraction that occurs when hydrogen is directly bonded to fluorine ($F$), oxygen ($O$), or nitrogen ($N$).

Isoelectronic

A term describing chemical species that have the exact same total number of electrons (such as argon and fluorine gas, each having $18$ electrons).

Network Covalent Solid

A continuous macroscopic structure made of millions of covalent bonds linking atoms throughout the entire solid rather than individual molecules (such as diamond, graphite, or quartz/$SiO_2$).