General Chemistry Fundamentals: Bonding, Aqueous Reactions, Stoichiometry, Atomic Theory, and Matter

A comprehensive vocabulary review covering chemical bonding, aqueous reactions, quantitative stoichiometry, atomic structure, and fundamental properties of matter.

Ionic Bond

A chemical bond formed by the complete transfer of valence electrons from an element of low ionization energy (metal) to an element of high electron affinity (nonmetal), held together by non-directional Coulombic charge interactions.

Covalent Bond

A chemical bond formed by the sharing of valence electrons between atoms, arising from the mutual attraction of two nuclei for the same electrons.

Octet Rule

The principle stating that atoms tend to gain, lose, or share electrons in order to achieve a total of 8 valence electrons in their outermost shell, giving them a stable noble gas electron configuration.

Sigma Bond ($\sigma$)

A covalent bond formed by the head-to-head or end-to-end overlap of atomic orbitals along the internuclear axis.

Pi Bond ($\pi$)

A covalent bond formed when two parallel $p$ orbitals overlap sideways after a $\sigma$ bond has already formed.

Formal Charge

The charge assigned to an atom in a molecule, calculated as $FC = V - \frac{B}{2} - L$, where $V$ is the valence electrons of the free atom, $B$ is the number of bonding electrons, and $L$ is the number of nonbonding or lone-pair electrons.

Free Radical

An odd-electron molecule or species containing an unpaired valence electron, making a complete octet impossible for every atom.

Expanded Octet

A hypervalent condition occurring in central atoms from Period 3 and beyond where the central atom accommodates more than 8 valence electrons.

Electrolyte

A substance that dissociates into ions when dissolved in water, producing a solution that conducts electricity.

Spectator Ions

Ions in a reaction mixture that do not undergo any chemical change from the reactant side to the product side and are omitted from the net ionic equation.

Oxidation

A chemical process characterized by the loss of electrons by a substance, resulting in an increase in its oxidation number.

Reduction

A chemical process characterized by the gain of electrons by a substance, resulting in a decrease in its oxidation number.

Molarity

A measure of solution concentration defined as the number of moles of solute per volume of solution in liters.

Titration

An analytical technique in which a standard solution of known concentration is used to determine the concentration of an unknown solution.

Law of Conservation of Mass

A foundational law formulated by Antoine Lavoisier stating that matter is neither created nor destroyed during a chemical process.

Theoretical Yield

The maximum quantity of product that can be generated in a chemical reaction, as calculated through stoichiometry from the limiting reactant.

Percent Yield

The percentage efficiency of a reaction calculated as $\text{Percent Yield} = \frac{\text{actual yield}}{\text{theoretical yield}} \times 100$.

Limiting Reactant

The reactant present in the smallest stoichiometric relative quantity that is completely consumed first, determining the maximum yield of product.

Isotopes

Atoms of the same element that contain the same number of protons but different numbers of neutrons, resulting in different mass numbers.

Atomic Weight

The average mass of an element calculated by summing the masses of all its naturally occurring isotopes weighted by their relative fractional abundances.

Isomers

Compounds that possess the exact same molecular formula but have different structural arrangements of their atoms.

Intensive Property

A property of matter that is independent of the amount of substance present, such as density, color, or boiling point.

Extensive Property

A property of matter that depends directly on the quantity of substance present, such as mass, volume, or total energy.

Precision

A measure of how closely individual experimental measurements agree with one another.

Accuracy

A measure of how closely an experimental value or average agrees with the true or standard value.

Distillation

A physical separation technique that separates components of a homogeneous mixture based on differences in their boiling points.

Law of Multiple Proportions

A law formulated by John Dalton stating that if two elements form more than one compound, the masses of one element that combine with a fixed mass of the other are in ratios of small whole numbers.

Law of Constant Composition

A law discovered by Joseph Proust stating that any sample of a given pure compound always contains the exact same elemental composition by mass.