An ion with a net negative charge.
An orbital that is associated with only one particular atom. This is in
contrast to molecular orbitals, which are spread across a collection of
German for "building up", a systematic procedure for determining the
electron configuration of any atom.
An ion with a net positive charge.
Orbitals with identical energies.
The energy change in an atom when it gains an electron.
First ionization energy
The energy cost of removing one electron from an atom.
A rule which says that electrons prefer to go in separate orbitals when
choosing between orbitals of the same energy, in order to half-fill orbitals.
Any atom or molecule with a net charge.
Bonding interaction that results from electrostatic attraction between
cations and anions.
The energy it takes to remove an electron from an atom.
Description for two elemental species with the same electronic configuration.
Atoms with the same number of protons (i.e. same atomic number) but a
different number of neutrons.
The cardinal rule of bonding. The octet rule states that atoms gain stability
when they have a full complement of 8 electrons in their valence shells.
The region around an atom where an electron has a high probability of being
Pauli Exclusion Principle
States that no two electrons in an atom or molecule can have the same set of four quantum numbers n, l, m, and s.
Second ionization energy
The energy cost of removing a second electron from an atom.
A group of subshells of similar energy levels. 2s and 2p subshells
the same shell.
When the attraction from the nucleus felt by one electron is lessened or blocked
by intermediate electrons. Shielding can split degenerate orbitals.
For example, since s-orbital electrons shield for p-orbital electrons and
receive little shielding themselves, s-orbitals are usually of lower energy
level than p-orbitals of the same shell.
The breaking of degenerate orbitals within a shell in multi-electron atoms.
Orbitals in an atom with the same energy; orbitals of the same subshell are of
the same shape. p-orbitals are of the same subshell, while s-orbitals are of
A tenet of quantum mechanics which says that the position and momentum of any
particle cannot both be known precisely at the same time.
The electrons in the outermost energy shell of an atom. The configuration of
these electrons determine the chemical properties of the element.
The highest energy shell in an atom. All interactions between atoms take
place through the electrons of the valence shell.