42 terms

incandescence

term for the production of visible light by a heated body

blackbody

term for an ideal absorber, which absorbs all the radiation that falls upon it

radiancy

term for the luminal energy emitted per unit time from a unit area

Stefan-Boltzmann law

term for the relationship betweent the radiated energy and the temperature of a blackbody

Wien's law

the law that states that the most strongly emitted wavelength is a function of temperature

quanta

the discrete amounts in which radiation is emitted, according to Planck

quantum theory

Max Planck's theory that radiation is emitted in discrete amounts when an electrically charged body oscillates

photoelectric effect

term for the ejection of electrons from a surface exposed to ultraviolet light or any other radiation

photoelectrons

term for the electrons ejected from a surface exposed to ultraviolet light or other radiation

work function

term for the amount of work that must be done to remove an electron from the outermost orbit of an outlying atom to a distance infinitely far away

saturation potential

term for a certain positive potential beyond which the current rises very little

stopping potential

term for a certain potential at which the current in a collector ceases

threshold frequency

term for the frequency above which photoemission occurs even if the light is extremely weak, and below which photemission never occurs

photons

term for the particles of which light consists

Compton effect

the effect that occurs when a block of graphite is placed in the path of a narrow beam of xrays, and the x-rays scatter in such a way that, at any angle of scattering, they are most intense at two wavelengths: the incident wavelength and a longer wavelength that increases as the scaterring angle increases

de Broglie's equation

the equation which states that the wavelength of any material particle or body is equal to Planck's constant divided by the product of mass and velocity

matter waves

When a property like wavelength is a factor, matter may be viewed as ___ ___.

wave-particle duality

the theory that matter exists simultaneously as both waves and particles, the particles moving in a manner dictated by the waves

complementarity

the concept that every quantum system exhibits both particle and wave properties, but the demonstration of one property limits the demonstration of the other at the same moment

quantum numbers

the four numbers that provide a statistical description of an electron's likelihood to be found in a given region where they will demonstrate observed characteristics

Pauli exclusion principle

the principle which states that no two electrons within an atom can have the same set of quantum numbers

orbital

term for the hollow, three-dimensional shape that shows positions of high probability for finding an electron around a nucleus

principal

The ____ quantum number (denoted n) indicates a specific energy level containing electrons at an average radius from the nucelus.

subshell

The ____ (denoted by l) indicates the possible orbitals within a given energy level.

node

term for the space beween two shells-- a place of low probablility for containing an electron

magnetic

The ____ quantum number (denoted m1) indicates the spatial orientation of an orbital.

spin

The ___ quantum number (denoted ms) differentiates the two electrons in the same orientation within the same orbital within the same energy level.

line emission spectra

term for the specific frequencies of radiation emitted by elements or compounds in gaseous form, which increase in intensity as a function of temperature

line absorption spectrum

term for the spectrum whose prominent lines are identical in location to the two prominent lines in the line emission spectrum of the same element

wavelengths

A gas emits the same ____ that is absorbs.

model

term for a theoretical picture of something

Niels Bohr

the Danish physicist who constructed a model of a hydrogen atom in order to predict the behavior of its electron

vary continuously

Bohr stated that the energy of a hydrogen atom's electron does not ___ ____.

quantized

term signifying that all the electrons within any atom are restricted to specific energy states

higher, lower

Bohr postulated that light is emitted by the hydrogen electron only when it moves from a ___ energy state to a ___ one.

visible light, radiation

Bohr proposed that light emited by the hydrogen electron during transition to a lower energy state takes the form a of a single photon with a frequency of ___ ___ or of ___ elsewhere on the spectrum.

unpredictable

Bohr claimed that the jumps of the hydrogen electron are esentially ____.

ground state

term for the lowest possible energy state of an electron

excited state

term for the higher energy state of an electron

wave mechanical model

Schrodinger's model which related an electron's energy state to a cyclical standing wave

wave function

According to the wave equation, ψ gives the value of the ___ ___ under a given set of conditions.

uncertainty principle

Heisenberg's principle which states that we know either an electron's position or momentum, but not both at the same time