hstmr.watson chapter 7 quantum theory of the atom
TRANSCRIPT
HSTMr.Watson
Chapter 7Chapter 7
Quantum Theory of the Atom
HSTMr.Watson
Electromagnetic RadiationElectromagnetic Radiation
Electromagnetic waveA wave of energy having a frequency
within the electromagnetic spectrum and propagated as a periodic disturbance of the electromagnetic field when an electric charge oscillates or accelerates.
HSTMr.Watson
Electromagnetic RadiationElectromagnetic Radiation
Electromagnetic wavewavelengthfrequency amplitude
HSTMr.Watson
Electromagnetic RadiationElectromagnetic Radiation
= c
where=> frequency
=> wavelength
c => speed of light
HSTMr.Watson
Wave Nature of the ElectronWave Nature of the Electron
HSTMr.Watson
Electromagnetic SpectrumElectromagnetic Spectrum
HSTMr.Watson
Line Emission SpectrumLine Emission Spectrum
HSTMr.Watson
Line SpectrumLine Spectrum
A spectrum produced by a luminous gas or vapor and appearing as distinct lines characteristic of the various elements constituting the gas.
HSTMr.Watson
Emission SpectrumEmission Spectrum
The spectrum of bright lines, bands, or continuous radiation characteristic of and determined by a specific emitting substance subjected to a specific kind of excitation.
HSTMr.Watson
Ground StateGround State
The state of least possible energy in a physical system, as of elementary particles. Also called ground level.
HSTMr.Watson
Excited StateExcited State
Being at an energy level higher than the ground state.
HSTMr.Watson
Photoelectric EffectPhotoelectric Effect
the emission of electrons by substances, especially metals, when light falls on their surfaces.
HSTMr.Watson
Photoelectric EffectPhotoelectric Effect
HSTMr.Watson
Quantum MechanicsQuantum Mechanics
Quantum theorythe theory of the structure and behavior of
atoms and molecules.
HSTMr.Watson
Black Body RadiationBlack Body Radiation
http://www.cbu.edu/~mcondren/C11599/BBvis.mov
HSTMr.Watson
Electromagnetic RadiationElectromagnetic Radiation
Ehi - Elo = hc/where E => energy
h => Planck's constant
c => speed of light
=> wavelength
HSTMr.Watson
PhotonsPhotons
The quantum of electromagnetic energy, generally regarded as a discrete particle having zero mass, no electric charge, and an indefinitely long lifetime.
HSTMr.Watson
Dispersion of White LightDispersion of White Light
HSTMr.Watson
The Atomic Spectrum of The Atomic Spectrum of HydrogenHydrogen
and the Bohr Model and the Bohr ModelBohr Model for the Hydrogen Atom
mnr = nh/2p
HSTMr.Watson
Bohr AtomBohr Atom
HSTMr.Watson
Bohr ModelBohr Model
E = -B/n2
where n => quantum number
1, 2, 3, 4, 5, 6, 7, etc
HSTMr.Watson
Bohr ModelBohr Model
for hydrogen
ground state: n = 1
excited state: n > 1
HSTMr.Watson
Bohr ModelBohr Model
E = (-2.179 X 10-18 J/part.)
(6.022 X 1023 part./mole)
(1 kJ/103 J)/n2
= (-1312 kJ/mol)(1/n2)
HSTMr.Watson
Electron Transition in a Hydrogen Electron Transition in a Hydrogen AtomAtom
Lyman series => ultraviolet
n > 1 ==> n = 1
Balmer series => visible light
n > 2 ==> n = 2
Paschen series => infrared
n > 3 ==> n = 3
HSTMr.Watson
Line SpectraLine Spectra
See CHEMWORKS software
HSTMr.Watson
Absorption SpectrumAbsorption Spectrum
Light shinning on a sample causes electrons to be excited from the ground state to an excited state
wavelengths of that energy are removed from transmitted spectra
HSTMr.Watson
Knowing diamond is transparent, which curve best represents the absorption spectrum of diamond (see below)?
A, B, C
HSTMr.Watson
According to the energy diagram below for the Bohr model of the hydrogen atom, if an electron jumps from E1 to E2, energy is
absorbed
emitted
not involved
HSTMr.Watson
Heisenberg, WernerHeisenberg, Werner1901–76, German physicist1901–76, German physicist
1932 Nobel Prize in physics1932 Nobel Prize in physics
A founder of QUANTUM MECHANICS, he is famous for his uncertainty principle, which states that it is impossible to determine both the position and momentum of a subatomic particle (such as the electron) with arbitrarily high accuracy.
HSTMr.Watson
Heissenberg Uncertainty Heissenberg Uncertainty PrinciplePrinciple
“it is impossible to determine both the position and momentum of a subatomic particle (such as the electron) with arbitrarily high accuracy”
The effect of this principle is to convert the laws of physics into statements about relative, instead of absolute, certainties.
HSTMr.Watson
OrbitalsOrbitals
region of probability of finding an electron around the nucleus
4 types => s p d fmaximum of 2 electrons per orbital
HSTMr.Watson
Pure Atomic OrbitalsPure Atomic Orbitals
shape # of orbitals / energy level
s spherical 1
p dumbbell 3
d complex 5
f very complex 7
HSTMr.Watson
Atomic Orbitals, s-Atomic Orbitals, s-typetype
HSTMr.Watson
Atomic Orbitals, p-Atomic Orbitals, p-typetype
HSTMr.Watson
Atomic Orbitals, d-typeAtomic Orbitals, d-type
HSTMr.Watson
Atomic Orbitals, f-typeAtomic Orbitals, f-type
HSTMr.Watson
Shapes of OrbitalsShapes of Orbitals
http://www.colby.edu/chemistry/OChem/DEMOS/Orbitals.html