Unit 4: Chemical Bonding and Nomenclature

Vocabulary flashcards covering chemical bonding types, electronegativity differences, molecular polarity, ionic crystal structure, and IUPAC nomenclature rules from Unit 4.

Chemical Bond

The force of attraction that holds $2$ atoms together.

Compound

A substance composed of $2$ or more elements chemically bonded together.

Molecule

$2$ or more atoms held together specifically by covalent bonds.

Ion

An atom or group of atoms that carries an electrical charge because it has lost or gained one or more electrons.

Cation

A positively charged ion formed when an atom (generally a metal) loses electrons.

Anion

A negatively charged ion formed when an atom (generally a nonmetal) gains electrons.

Octet Rule

The principle stating that in forming compounds, atoms of elements lose, gain, or share electrons in such a way as to produce a noble gas electron configuration (filled outermost $s$ and $p$ orbitals with $8$ valence electrons, or $2$ for helium).

Ionic Bonding

The electrostatic force of attraction that holds oppositely charged particles (cations and anions) together following the transfer of electrons from one atom to another, typically between metals and nonmetals.

Covalent Bonding

A type of chemical bonding that results from the sharing of valence electrons between $2$ atoms, typically between nonmetals.

Non-polar Covalent Bond

A covalent bond formed between $2$ atoms of the same element or elements with similar electronegativities, having an electronegativity difference between $0$ and $0.3$ (exhibiting $0\%$ to $5\%$ ionic character).

Polar Covalent Bond

A covalent bond in which the bonded atoms have an unequal attraction for the shared electrons, corresponding to an electronegativity difference between $0.3$ and $1.7$ (exhibiting $5\%$ to $50\%$ ionic character).

Bond Polarity

A property that measures the degree of unequal sharing of electrons between $2$ bonded atoms.

Molecular Polarity

A property that measures the degree of unequal sharing of electrons across an entire molecule, which depends on dipole moments and the three-dimensional molecular shape.

Polar Molecule

A molecule characterized by an asymmetrical distribution of bond polarity, resulting in a separation between the center of positive charge and the center of negative charge.

Non-polar Molecule

A molecule characterized by a symmetrical distribution of bond polarity, resulting in no separation between the centers of positive and negative charge.

Formula Unit

The smallest whole-number ratio of ions in an ionic compound that balances total electrical charge to maintain electrical neutrality.

Polyatomic Ion

A group of atoms held together by covalent bonding that carries an overall net positive or negative charge.

Oxyanion

A polyatomic ion that contains oxygen combined with another element (such as nitrate, $\text{NO}_3^-$, or sulfate, $\text{SO}_4^{2-}$).

Nomenclature

A systematic method and set of rules used for naming chemical compounds.

IUPAC

The International Union of Pure and Applied Chemistry, the governing organization that establishes standard chemical nomenclature rules.

Binary Ionic Compound

An electrically neutral ionic compound composed of only two elements (a metal cation written first and a nonmetal anion written second with the suffix "-ide").

Stock System of Nomenclature

A naming system that uses Roman numerals in parentheses immediately following the metal's name to specify the charge or oxidation state of a cation that can form more than one possible charge.