spectroscopy Flashcards
order of electromagnetic radiation in order of decreasing wavelength
radio waves, microwaves, infrared radiation, visible light, ultraviolet light, x rays, gamma rays.
visible spectrum wavelength range
390nm to 700nm
ground state electrons
electrons which have absorbed no energy and are in their lowest energy shell.
excited electrons
electrons which have absorbed energy to promote them to higher energy shells.
wavelength and frequency equation
C = vλ
speed of light = frequency x wavelength
energy of a photon equation
E = hv
energy = plancks constant x frequency
Planck’s constant
6.626 x 10 ^-34 Js
Avogadro’s constant
The number of atoms/ species in one mole
6.02 x 10^23 mol^-1
wavelength and wavenumber ratio
λ = 1/v*
v* in cm^-1 and λ in m so also use conversion rate.
frequency and period relationship
v = 1/T
frequency = 1 / period
period definition
the number of seconds per wave
wavenumber
the number of waves per cm
electron volts to joules
1eV = 1.602 x 10 ^ -19 J
relating energy and wavelength/ frequency equations
C = vλ and E =hv
v = C/λ
E = h(C/λ)
v* = 1/λ
E = hCv*
photon definition
Electromagnetic radiation which behaves as a particle.
frequency and energy rule for electromagnetic radiation
as the frequency increases the energy of electromagnetic radiation will increase
rule for energy absorbed by an electron
the energy an electron will absorb is not the energy of the energy shell it is currently in or promoted to, it the the energy gap, or difference in energy between the two energy shells.
Rydberg equation
E = RH/n^2
energy = Rydberg’s constant / (principal quantum number)^2
Rydberg’s constant
RH = 13.6 eV
energy gap of an electron equation
ΔE = RH( 1/n^2 - 1/ n^2)
where n = n1 and n = n2
n1< n2
basically the energy must be positive because its an energy gap
series of energy transitions
lyman : n =1
balmer : n = 2
paschen : n = 3
bracket : n = 4
pfund : n = 5
where n is the lower energy shell
basic quantum numbers of electrons
n , l , ml, ms
n quantum number
the principal quantum number referring to electron energy shell
l quantum number
the angular momentum quantum number shows the position and the momentum ( mass x velocity)