Net Ionic Equation

An equation that indicates only the ionic species that actually take part in the reaction.

Neutralization Reaction

A reaction between an acid and a base.

Neutron

A subatomic particle that bears no net electric charge. Its mass is slightly greater than a proton’s.

Newton

The SI unit for force.

Nitrile

An organic compound containing —CºN: group.

Nitro

An organic grouping that contains –NO₂.

Nitrogen Fixation

The conversion of molecular nitrogen into nitrogen compounds.

Noble Gas Core

The electron configuration of the noble gas element that most nearly precedes the element being considered.

Noble Gases

Nonmetallic elements in Group 8A (He, Ne, Ar, Kr, Xe, and Rn).

Nonbonding Electrons

Valence electrons that are not involved in covalent bond formation.

Nonelectrolyte

A substance that, when dissolved in water, gives a solution that is not electrically conducting.

Nonmetals

Elements that are usually poor conductors of heat and electricity.

Nonpolar Molecule

A molecule that does not possess a dipole moment.

Nonvolatile

Does not have a measurable vapor pressure.

n-Type Semiconductors

Semiconductors that contain donor impurities.

Nuclear Binding Energy

The energy required to break up a nucleus into its protons and neutrons.

Nuclear Chain Reaction

A self-sustaining sequence of nuclear fission reactions.

Nuclear Fission

A heavy nucleus (mass number . 200) divides to form smaller nuclei of intermediate mass and one or more neutrons.

Nuclear Fusion

The combining of small nuclei into larger ones.

Nuclear Transmutation

The change undergone by a nucleus as a result of bombardment by neutrons or other particles.

Nucleic Acids

High molar mass polymers that play an essential role in protein synthesis.

Nucleophile

An ion, molecule, or chemical intermediate that provides a pair of electrons to react with.

Nucleotide

The repeating unit in each strand of a DNA molecule which consists of a base-deoxyribose-phosphate linkage.

Nucleus

The central core of an atom.