ch. 29 Flashcards
what does light emitted by a gas discharge tube contain?
only discrete wavelengths
every wavelength that is absorbed is also _______ but not every ______ is absorbed
every wavelength that is absorbed is also emitted but not every wavelength that is emitted is also absorbed
what is the atomic number
it is the number of protons or electrons in a neutral atom
what is Z
Z is the number of protons in the nucleus
what is N
N is the number of neutrons
what is A
it is the mass number which is the number of protons plus the number of neutrons which is in the unit of atomic unit u
what are isotopes
isotopes are atoms of the same element with the same number of protons but they differ in the number of neutrons
what are stationary states
they are particular arrangements of electrons in allowed orbits
Eahc stationary state has a discrete, well-defined:
Energy En that is quantized
what is a transition or quantum jump of an atom
it is when an electron in an atom absorbs or emits a photon when jumping to higher or lower stationary states
what is collisional excitation
atoms can move from lower to higher energy states by absorbing energy in a collision with a high energy electron
what spectra do atoms emit
they emit a discete spectrum where the energy of the photon emitterd or absorbed is equal to the energy difference between the two states
what is the balmer series
it is consisting of transitions ending on the m=2 state, gives visible wavelengths
what is the lyman series
it ends on the m=1 state and is in the utltra violet region of te spectrum
what is the principal quantum number
it defines the energy of hydrogen atoms
what is L and how does it relate to l
L is the angular momentum of the orbit and l is the orbital quantum number
what is m
it is the magnetic quantum number and it is the tilt of the orbit
what is ms
it is the spin quantum number which can point up or down
what are the four quantum numbers
n, l, m, ms
what are the values of l and the symbols
if l=0 it is s
if l=1 it is p
if l=2 it is d
if l = 3 it is f
what value is l in relation to n
it is l ≤ n-1
what is m in relation to l
-l ≤ m≤ l
what is ms
it is +1/2 or -1/2
if the subshell is s, what is the value of l,m and the number of states
l=0, m=0, two states possible (up or down)
if the subshell is p, what is the value of l,m and the number of states
l=1, m= -1,0,1, there are 6 possible states (3m*2)
if the subshell is d, what is the value of l,m and the number of states
l is 2, m is 2,1,0,-1,-2
there are 10 possible states
if the subshell is f, what is the value of l,m and the number of states
l=3
m=3,2,1,0,-1,-2,-3
there are 14 states
if a multi-electron atom, for each n what happens to l
for each n, the energy increases as l increases
what is the order of orbital filling for the 3-4 levels
3s3p4s3d
3d is higher energy to it fills later
what is the pauli exclusion principle
no two numbers can have the same set of quantum numbers
when does collisional excitation occur
when the energy of the particle exceeds the energy change
what do x-rays do to inner electrons
they knock them loose and cause inner shell valancy
when an innershell electron is knocked loose by an Xray, what occurs
an electron from a higher shell undergoes a quantum jump and emits a photon
what is fluorescence
it is when the absorption of light at a higher frequency (shorter wavelength) is then emitted as longer wavelength, lower frequnecy light
what is a stimulated emission, what does it produce
it occurs when the energy of a photon is exacty equal to the energy difference between two states., this causes a photon to be emitted when the transition occurs
the incident photon is not absorbed so there are now two identical incident photons
