CH. 6 Flashcards
refers to the number of electrons in the atom as well as their distribution around the nucleus and their energies
electronic structure
form of energy that has wave characteristics and that propagates through a vacuum at 2.998x10^8 *(the speed of light)
electromagnetic radiation (radiant energy)
distance between two adjacent peaks
wavelength
number of complete wavelengths (cycles) that pass a given point each second
frequency
do all electromagnetic radiation move at different speeds
no (they all move at the same speed, the speed of light)
cycles per second
hertz
frequency is expressed in ____
hertz
what are the three observations that can be made about the wave model of light
blackbody radiation, photoelectric effect, emission spectra
the emission of light from hot objects
blackbody radiation
the emission of electrons from metal surfaces on which light shines
photoelectric effect
the emission of light from electronically excited gas atoms
emission spectra
when solids are heated they emit _____
radiation
smallest amount of energy that can be emitted or absorbed as electromagnetic radiation
quantum
who proposed that energy can be either released or absorbed by atoms only in discrete chunks of some minimum size (won the noble prize for quantum theory)
max planck
6.626x10^-34
plancks constant
who proposed the photoelectric effect
albert einstein
particles of energy
photon
each photon must have the energy equal to the ____ ____ times the ____ of the ____
plancks constant, frequency, light
who offered a theoretical explanation of line spectra
niels bohr
radiation composed of a single wavelength is
monochromatic
radiation containing many different wavelengths
polychroamtic
produced when radiation from a polychromatic source is separated into its component wavelengths
spectrum
rainbow of colors containing light of all wavelengths
continuous spectrum
spectrum containing radiation of only specific wavelengths
line spectrum
what are the three postulates of bohrs model
only orbits of certain radii are permitted for the electron in a hydrogen atom, an electron in a permitted orbit is in an allowed energy state (an electron
what are the three postulates of bohrs model
only orbits of certain radii are permitted for the electron in a hydrogen atom, an electron in a permitted orbit is in an allowed energy state (an electron
what are the three postulates of bohrs model
only orbits of certain radii are permitted for the electron in a hydrogen atom
an electron in a permitted orbit is in an allowed energy state, an electron in an allowed energy state does not radiate energy and does not spiral into the nucleus
energy is emitted or absorbed by the electron only as the electron changes from one allowed energy state to another
the lower (more negative) the energy is, the more ___ the atom is
stable
the lowest energy state
ground state
when the electron is in a higher-energy state
excited state
the energy of the photon must ____ the difference in energy between the two states
equal
when change of e (delta e) is positive, a photon must be ____ as the electron jumps to a higher energy
absorbed
when change of e (delta e) is negative, a photon is ___ as the electron falls to a lower energy level
emitted
what are three limitations of the bohr model
cannot explain the spectra of other atoms, does not explain why the negatively charged electron would not just fall into the positively charged nucleus, electron orbiting the nucleus at a fixed distance is not accurate
what are two important ideas of the bohr model
electrons exist only in certain discrete energy levels (described by quantum numbers), energy is involved in the transition of an electron from one level to another
who proposed that an electron moving about the nucleus of an atom behaves like a wave and has a wavelength
louis de broglie
describes the wave characteristics of material particles
matter waves
when applied to the electrons in an atom, this principle states that it is impossible for us to know simultaneously both the exact momentum of an electron and its exact location in space
uncertainty principle
mathematical functions that describe the electron in the atom
wave functions
photon or particle exists simultaneously in two different quantum states
cat state
collection of orbitals with the same value of n
electron shell
set of orbitals that have the same n and l values
subshell
the shell with principal quantum number n consists of exactly ___ subshells
n
each subshell consists of a specific number of ____
orbitals
the total number of orbitals in a shell is ___, where n is the principal quantum number of the shell
n2
the electron density for the s orbitals are
spherically symmetric (electron density at a given distance from the nucleus is the same regardless of the direction in which we proceed from the nucleus)
for an ns orbital the number of peaks is equal to __ with the outermost peak being larger than inner ones
n
for an ns orbital the number of nodes is equal to
n-1
as n increases, the electron density becomes __ spread out, there is a greater probability of finding the electron further from the nucleus
more
in a many electron atom, for a given value of n, the energy of an orbital increases with increasing value of
1
orbitals with the same energy are said to be
degenerate
intrinsic property that causes each electron to behave as if it were a tiny sphere spinning on its own axis
electron spin
states that no two electron in an atom can have the same set of four quantum numbers (n, l, m1, ms)
pauli exclusion principle
an orbital can hold a maximum of ___ electrons and they must have _____ spins
two, opposite
the way electron are distributed among various orbitals of an atom
electron configuration
the orbitals are filled in order of ___ energy, with no more than ___ electrons per orbital
increasing, 2
represents an electron with a positive spin magnetic quantum number
half arrow pointing up
represents an electron with a negative spin magnetic quantum number
half arrow pointing down
when filling degenerate orbitals the lowest energy is attained when the number of electrons having the same spin is maximized (electrons occupy orbitals singly to the maximum extent possible and that these single electrons in a given subshell all have the same spin magnetic quantum number)
hunds rule
the 14 elements corresponding to the filling of the 4f oribtals are known as
lanthanide elements (rare earth elements)
the s block and the p block elements together are the
representative elements (main group elements)
elements in which the valence d orbitals are being filled and make up the d block
transition metals
for representative elements we do not consider the electrons in completely filled d or f subshell to be ___ ___
valence electrons
for transition elements we do not consider the electrons in a completely filled f subshell to be _____ ____
valence electrons
there is an ___ relationship between frequency and wavelength
inverse
