Why do we add energy? Shouldn’t the gas glow all by itself without any help?
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Transcript of Why do we add energy? Shouldn’t the gas glow all by itself without any help?
Part 3(e): Atomic Physics
Bohr Model of the Atom
Important point:
* Each atom has a unique set of orbits* Each atom produces a unique set of wavelengths when it produces em waves
Part 3(e): Atomic Physics
Bohr Model of the Atom
Important point:
* Each atom has a unique set of orbits* Each atom produces a unique set of wavelengths when it produces em waves* The spectrum of the element can be usedas a “fingerprint” to identify the element
Part 3(e): Atomic Physics
Emmission Spectra for Various Atoms
Part 3(e): Atomic Physics
Bohr Model of the Atom
The Energy Minimun Principle
* The electrons in orbit will existed in theorbit with the lowest possible energy state.
Part 3(e): Atomic Physics
Bohr Model of the Atom
The Exclusion Principle
* No two electrons in an atom will have thesame energy.
Part 3(e): Atomic Physics
Bohr Model of the Atom
Implication
* For atoms with more than one electron, theelectrons will “stack” with the firstelectron in the lowest possible energy state,the second in the second lowest, etc.
Part 3(e): Atomic Physics
Bohr Model of the Atom
Why do we add energy? Shouldn’t the gas glow all by itself without any help?
Yes, but the electrons will populate the lowest energy state. In order to see the spectra to the fullest, energy is used to populate excited states and let the electrons cascade down through the orbits, producing as many characteristic photons as possible.
http://jersey.uoregon.edu/elements/Elements.html
Periodic Table with Spectra
Part 3(e): Atomic Physics
Absorption Spectrum
Part 3(e): Atomic Physics
Absorption Spectrum
Gas
Part 3(e): Atomic Physics
Absorption Spectrum
http://jersey.uoregon.edu/elements/Elements.html
Periodic Table with Spectra
Periodic Table with Spectra
What would an absorption spectrum look like to a computer?
Periodic Table with Spectra
What would an absorption spectrum look like to a computer?
An exercise for the reader
Part 3(e): Atomic Physics
Incandescence
Part 3(e): Atomic Physics
Incandescence
ContinuousSpectrum
Part 3(e): Atomic Physics
Spectral Properties of Incandescence
Energy
Wavelength
Part 3(e): Atomic Physics
Spectral Properties of IncandescenceEnergy
WavelengthBlue Red
Low Temp
High Temp
Part 3(e): Atomic Physics
Spectral Properties of IncandescenceEnergy
WavelengthBlue Red
Low Temp
High Temp
Part 3(e): Atomic Physics
Spectral Properties of IncandescenceEnergy
WavelengthBlue Red
Low Temp
High Temp
Click here to view a temperature adjustable continuous spectrum