Ch 8- The Atom Flashcards
the emission of electrons from a metal surface when light shines on it
Photoelectric effect
who developed the quantum theory of light
Albert Einstein
Einstein’s quantum theory of light was based on a hypothesis suggested by the German physicist
Max Planck
light emitted by a hot object is given off in discrete units
quanta
the equation that shows all the quanta associated with a particular frequency of light have the same energy
E=hf
Planck’s constant
6.63x10-34Jpersec
equation for photoelectric effect is
hf=KE+w
who discovered the X-ray
Wilhelm Roentgen
Louis de Broglie proposed that moving objects behave like waves
matter waves
the quantity that varies in a matter wave is called
wave function
the square of the wave function is called
the probability density
the principle that states that it Is impossible to know both the exact position and momentum of a partible at the same time
Heisenberg’s uncertainty principle
an instrument that disperses the light emitted by an excited gas into the different frequencies the light contains
spectroscope
spectrum that consists of all frequencies of light given off by an excited substance
emission spectrum
consists of the various frequencies absorbed by a substance when white light is passed through it
absorption spectrum
frequencies in the spectrum of an element fall into sets called
spectral series
an atom having the lowest possible energy is in its
ground state
an atom that has absorbed energy is an
excited state
excited states with relatively long lifetimes
metastable states
n governs the electron’s energy and average distance from the nucleus
principle quantum number
l determines the magnitude of an atomic electron’s angular momentum
orbital quantum number
m1 specifies the direction of an atomic electron’s angular momentum
magnetic quantum number
m8 of an atomic electron has two possible values +1/2 or -1/2, depending on whether the electron aligns itself along a magnetic field or opposite to the field
spin magnetic quantum number
states that only one electron in an atom can exist in a given quantum state
exclusion principle
