electromagnetic radiation
a form of energy exhibiting wavelike behavior as it travels through space
wavelength
the shortest difference between equivalent points on a continuous wave
frequency
the number of waves that pass a given point per second
amplitude
the height of a wave from the origin to a crest, or from the origin to the trough
electromagnetic spectrum
includes all forms of electromagnetic radiation which vary in their frequencies and wavelength
quantum
the minimum amount of energy that can be gained or lost by an electron
Planck's constant
constant number in Joules times seconds
photoelectric effect
a phenomenon in which photoelectrons are emitted from a metal's surface when light of a certain frequency shines on the surface
photon
a particle of electromagnetic radiation with no mass that carries a quantum of energy
atomic emission spectrum
a set of frequencies of electromagnetic waves given off by atoms of an element; consists of a series of fine lines of individual colors
ground state
the lowest allowable energy state of an atom
quantum number
the number assigned to each orbit of an electron
de Broglie equation
predicts that all moving particles have wave characteristics and relates each particle's wavelength to its frequency, its mass, and Planck's constant
Heisenberg uncertainty principle
states that it is not possible to know precisely both the velocity and the position of a particle at the same time
quantum mechanical model of the atom
an atomic model in which electrons are treated as waves; also called the wave mechanical model of the atom
atomic orbital
a three-dimensional region around the nucleus of an atom that describes an electron's probable location
principle quantum number
assigned by the quantum mechanical model to indicate the relative sizes and energies of atomic orbitals
principle energy level
the major energy levels of an atom
energy sublevels
the energy levels contained within a principle energy level
electron configuration
the arrangement of electrons in an atom, which is prescribed by three rules--the aufbau principle, the Pauli exclusion principle, and Hund's rule
aufbau principle
states that each electron occupies the lowest energy orbit available
Pauli exclusion principle
states that a maximum of two electrons can occupy a single atomic orbital but only if the electrons have opposite spins
Hund's rule
states that single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbitals
electron-dot structure
consists of an element's symbol, representing the atomic nucleus and inner-level electrons, that is surrounded by dots, representing the atom's valence electrons
s" orbital
sphere shaped
p" orbital
figure eight shaped
d" orbital
clover shaped
f" orbital
daisy shaped