Term
| Describe the phenomenon of black body radiation |
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Definition
| As an object is heated there is a shift from red->white->Blue as e/m goes from low frequencies to high frequencies |
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Term
| Explain what is meant by ultraviolet catastrophe |
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Definition
| a prediction by Rayleigh-Jeans Law that as temp increase the radiant energy density should diverge at ν^2 and enter the uv region |
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Term
| Explain the relevance of the Rayleigh-Jeans law |
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Definition
| a classical physics approach at relating intensity and frequency of blackbody radiation to temp |
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Term
| Explain the assumption Planck made to derive the distribution law |
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Definition
| Assumption was that the energy oscillators where discrete and proportional to an integer multiple of frequency E-nhν. This hold true for all Temp and ν if h=Planck's constant |
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Term
| Describe the agreement btwn the Planck distribution law and experimental data of blackbody radiation |
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Definition
| Planck's distribution for black body radiation was in agreement w/ experimental data at all temps and ν if h = Planck's constant |
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Term
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Definition
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Term
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Definition
| Planck's distribution Law |
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Term
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Definition
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Term
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Definition
| the alt Wein displacement law |
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Term
| Describe what what wein's displacement says |
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Definition
| Relates the max wavelength from an e/m distribution emitted from a black body to temperature |
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Term
| How does weins law provide evidence for plancks law? |
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Definition
| Provides an empirical relation to plancks law for temp and wavelength if h=plancks constant |
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Term
| How was Planck's law view by his contemporaries |
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Definition
| They believed his assumption was an arbitrary deviation and that there should be something that obeyed classical physics |
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Term
| What was the Significance of Planck's assumption to quantum mech |
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Definition
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Term
| Describe the photo electric effect |
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Definition
| Is the ejection of an electron from the surface of a metal by a photon that has a frequency exceeding the threshold frequency of the metals work function |
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Term
| What are the 3 experimental observations for the photoelectric effect |
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Definition
1)KE of ejected electron is independent of radiation intensity
2)There is a min threshold frequency need to eject an electron
3)Above threshold frequency, electron KE varies linearly |
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Term
| Define threshold frequency |
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Definition
| min frequency required to eject electron from surface of metal |
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Term
| Define threshold wavelength |
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Definition
| min wavelength required to eject electron from surface of metal |
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Term
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Definition
| Analogous to ionization energy. Min amount of energy required by photon to eject electron |
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Term
| Describe Einstein’s explanation of the photoelectric effect |
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Definition
| Radiation exists in small packets of energy called photons. The KE of ejected electron is equal to the energy of the photon minus the min energy to remove electron |
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Term
| Identify Einstein's key equation |
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Definition
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Term
| Explain how the value of Planck’s constant from photoelectric effect experiments compared to the value of Planck’s constant from blackbody radiation experiments |
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Definition
| The value of Planck's constant in both cases equaled that of Planck's constant from blackbody radiation. |
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Term
| Explain the significance of plancks constant to the development of quantum mechanics. |
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Definition
| Determined energy was quantized, which was significat to the development of quantum mech |
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Term
| Qualitatively describe the appearance of hydrogen emission spectra and how they are obtained. |
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Definition
| Subjecting hydrogen to high temp or electric discharge causes each atom to emit electromagnetic radiation of characteristic frequencies |
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Term
| Explain what a line “series” is in an emission spectrum |
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Definition
| The lines in an emission spectrum consist of only discrete frequencies. |
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Term
| how are the lines in a series emission spectra related? |
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Definition
| The lines in each series are related by an n quantum # that an excited eclecton relaxes to |
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Term
| how are the lines in different series emission spectra different? |
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Definition
The difference for each series is what quantum state the electron relaxes to.
Lymann n=1
Balmer n=2
Paschen n=3
Brackett n=4 |
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Term
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Definition
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Term
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Definition
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Term
| State the Ritz combination rule |
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Definition
| Stater that all observed spectra lines for all atoms can be expressed as a difference of terms |
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Term
| Describe what is meant by “the wave-particle duality of light”. |
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Definition
| Mean that a photon of light has both wave properties (ex. diffraction) and particle properties (ex. photoelectric effect) |
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Term
| Describe de Broglie’s idea about wave-particle duality and matter. |
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Definition
| de Broglie postulated that if light had wave particle properties, matter should also exhibit wave-particle duality |
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Term
Describe the classical diffraction pattern exhibited by x-rays and electrons and how it relates to the concept of wave-particle
duality. |
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Definition
| Electrons exhibit a wavelength similar to that of x-rays. In both instances, when the wave interacts w/ an atom in a lattice, the wave front propagate around it exhibiting the same light and dark interference patterns. this experiment demonstrates the wave nature of electrons |
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Term
| Identify the de Broglie equation. |
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Definition
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Term
| Define the de Broglie wavelength. |
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Definition
| The de Broglie wavelength is equal to planck's constant divided by the momentum of a particle |
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Term
| Describe the Bohr model of the atom |
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Definition
| Is the theory that explains the hydrogen atomic spectrum |
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Term
| Identify the two forces on the electron that are in balance |
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Definition
| Coulomb force and centripetal force |
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Term
| State Bohr’s two nonclassical assumptions. |
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Definition
1) There are stationary electron orbitals
2) The de Broglie wave of an electron must be in phase after a complete revolution |
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Term
| Define “ground-state energy” |
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Definition
| The lowest energy electron configuration of an atom |
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Term
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Definition
| An electron configuration of an atom other than the lowest energy state |
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Term
| Explain how the energy states are considered “bound states |
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Definition
| The electron is bound in the atom and in order to get an electron from n=1 to n=infinity requires energy |
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Term
| Draw the transition of the different hydrogen emission series on the energy level diagram |
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Definition
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Term
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Definition
| the equation for the radius of the bohr orbit |
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Term
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Definition
| the equation for energy of electron |
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Term
| Describe the problem encountered in trying to measure the position of an electron with light. |
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Definition
| The photon used to locate the electron imparts a momentum to the electron while locating it. As a result, you know the location of the electron w/ in the width of the photons wavelength, but you introduced an uncertainty in the momentum |
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Term
| Identify Uncertainty principle equations |
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Definition
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