Ideal Gas

A hypothetical gas whose pressure-volume-temperature behavior can be completely accounted for by the ideal gas equation.

Ideal Gas Equation

An equation expressing the relationships among pressure, volume, temperature, and amount of gas (PV = nRT, where R is the gas constant).

Ideal Solution

Any solution that obeys Raoult’s law.

Indicators

Substances that have distinctly different colors in acidic and basic media.

Induced Dipole

The separation of positive and negative charges in a neutral atom (or a nonpolar molecule) caused by the proximity of an ion or a polar molecule.

Inert Complex

A complex ion that undergoes very slow ligand exchange reactions.

Inorganic Compounds

Compounds other than organic compounds.

Insulator

A substance incapable of conducting electricity.

Intensive Property

A property that does not depend on how much matter is being considered.

Intermediate

A species that appears in the mechanism of the reaction (that is, the elementary steps) but not in the overall balanced equation.

Intermolecular Forces

Attractive forces that exist among molecules.

International System of Units

A system of units based on metric units.

Intramolecular Forces

Forces that hold atoms together in a molecule.

Ion

An atom or group of atoms that has a net positive or negative charge.

Ion Pair

A species made up of at least one cation and at least one anion held together by electrostatic forces.

Ion-Dipole Forces

Forces that operate between an ion and a dipole.

Ionic Bond

The electrostatic force that holds ions together in an ionic compound.

Ionic Compound

Any neutral compound containing cations and anions.

Ionic Equation

An equation that shows dissolved species as free ions.

Ionic Radius

The radius of a cation or an anion as measured in an ionic compound.

Ionization Energy

The minimum energy required to remove an electron from an isolated atom (or an ion) in its ground state.

Ionosphere

The uppermost layer of the atmosphere.

Ion-Product Constant

Product of hydrogen ion concentration and hydroxide ion concentration (both in molarity) at a particular temperature.

Isoelectronic

Ions, or atoms and ions. that possess the same number of electrons, and hence the same ground-state electron configuration, are said to be isoelectronic.

Isolated System

A system that does not allow the transfer of either mass or energy to or from its surroundings.

Isomer

One of two or more compounds with the same molecular formula but different properties, generally as a result of different arrangement of atoms.

Isotopes

Atoms having the same atomic number but different mass numbers.