Chapter 6 Flashcards
interference pattern
when light passes through two closely spaced slits
constructive interference
result of adding waves that are in phase
destructive interference
result of adding waves that are out of phase
speed of light (c)
3.00e8 m/s
speed of light equation
c = (wavelength)(frequency)
- (wavelength) = meters
- (frequency) = s^-1
blackbody radiation
when a solid is heated, it emits electromagnetic radiation over a wide range of wavelengths
Max Planck
suggested that radiant energy is only emitted or absorbed in discrete quantities or bundles
quantum (of energy)
smallest quantity of energy that can be emitted (or absorbed)
quantum theory formula
E = h(nu)
- E = energy in Joules
- nu = frequency
- h = Planck’s constant = 6.63e-34 Jxs
photoelectric effect
Einstein; electrons are ejected from the surface of a metal exposed to light of a certain threshold frequency
photons
Einstein proposed; light is a stream of particles
photon quantum theory equation
Photon = h(nu)
- where nu is at the threshold frequency
Heisenberg uncertainty principle
it is impossible to know simultaneously both the momentum and the position of a particle with certainty
Heisenberg uncertainty principle formula
(delta)x x (delta)p >= h/4(pi)
- (delta)x = uncertainty in position in meters
- (delta)p = uncertainty in momentum (mass x velocity)
Planck’s constant
6.63e-34 Jxs
Pauli exclusion principle
no two electrons can have the same four quantum numbers
Electron configuration
describes how the electrons are distributed in the atomic orbitals
Aufbau principle
electrons are added to the lowest energy orbitals first before moving to higher energy orbitals
Bohr’s Theory of the hydrogen atom
All wavelengths of visible light are present in the emission spectra of sun light and a heated solid
Line spectra
emission of light only at specific wavelengths
Bohr showed that the energies of the electron in a hydrogen atom are given by the equation
En = -2.18x10^18J(1/n^2)
Lowest energy state (n=1)
ground state
The stability of the electron decreases…
as n increases
n>1
excited state
Louis De Broglie
if light can behave like a
stream of particles (photons), then electrons could exhibit
wavelike properties.
According to deBroglie, electrons behave like
standing waves
The particle and wave properties are related by the
following expression:
lambda = h/mu
- m = mass (kg)
- u - velocity (m/s)
Quantum numbers describe
the distribution of electron
density in an atom
Principal quantum number
(n) - specifies size
Angular moment quantum number
(l) - specifies shape
Magnetic quantum number
(ml) - specifies orientation
s orbitals
spherical
p orbitals
hourglass shaped
d orbitals
two hourglasses
f orbitals
christmas lights
electron spin quantum number
(ms) - used to specify an electrons spin
- either +1/2 or -1/2
