a form of energy that exhibits wavelike behavior as it travels through space. examples are visible light, visible light from the sun, microwaves, x-rays and radio waves.
represented by λ, the greek letter lambda. the shortest distance between equivalent points on a continuous wave. the wavelength is measured from crest to crest or from trough to trough. usually expressed in meters, centimeters or nanometers.
represented by v, the greek letter nu. the number of waves that pass a given point per second. one hertz equals on wave per second.
the height of a wave from the origin to a crest or from the origin to a trough.
also called the em spectrum. encompasses all forms of electromagnetic radiation, with the only differences in the types of radiation being their frequencies and wavelengths.
the minimum amount of energy that can be gained or lost by an atom.
the german physicist who demonstrated mathematically that the energy of a quantum is related to the frequency of the emitted radiation by the equation E(quantum)=hv.
relates to the planck equation, E(quantum)=hv. the variable e is energy, the variable h is plancks constant and the variable v is frequency. plancks constant is measured in joules.
electrons, called photoelectrons, are emitted from the surface of a metal when light of a certain frequency shines on the surface.
photoelectric cells convert the energy of incident light into electrical energy.
a particle of electromagnetic radiation with no mass that carries a quantum of energy.
photon energy equation
E(photon)=hv. the variable e is energy, the variable h is plancks constant and the variable v is frequency.
atomic emission spectrum
the set of frequencies of the electromagnetic waves emitted by atoms of the element.
the lowest allowable energy state of an atom.
de broglie equation
λ=h/mv. the variable λ is wavelength, the variable h is plancks constant, the variable m is a particle of mass and the variable v is velocity.
heisenberg uncertainty principle
it is fundamentally impossible to know precisely both the velocity and position of a particle at the same time.
quantum mechanical model of the atom
the atomic model in which electrons are treated as waves. also called the wave mechanical model of the atom.
a three-dimensional region around the nucleus that describes the probable location of the electron.
principal quantum numbers
numbers that indicate the relative sizes and energies of atomic orbitals.
principal energy levels
the major energy levels of atoms. the lowest principal energy level is assigned a principal quantum number of one.
principal energy level one consists of a single sublevel, principal energy level two consists of two sublevels and so on.
the arrangement of electrons in an atom.
ground-state electron configuration
the most stable, lowest-energy arrangement of the electrons in atoms of each element.
each electron occupies the lowest energy orbital available.
pauli exclusion principle
a maximum of two electrons may occupy a single atomic orbital, but only if the electrons have opposite spins.
single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbitals.
electrons in the outermost orbitals of an atom, generally those orbitals associated with the highest principal energy level of an atom.
the symbol of the electron, which represents the atomic nucleus and inner-level electrons, surrounded by dots representing the valance electrons of the atom.
em wave relationship
energy of a quantum
energy of a photon
energy change of an electron
ΔE=E(higher-energy orbit) subtract E(lower energy orbit). ΔE=E(photon)=hv.