CEM 141 MSU Exam 2 |123
Accurate Q’s and A’s
Lights acts as what? - -Particle and wave.
- Wavelength - -The distance (m) of waves from peak to peak. Short: x-ray
(red), long: infrared (blue)
Short - higher energy
Long - lower energy
- Frequency (V) - -The number of wavefronts per second. Highest: x-ray
- Velocity of Light - -C = 3.00 X 10^8
= wavelength X frequency
- Amplitude - -The intensity, height of peaks of waves. Highest: blue light
- Energy of Wave (J) - -Increases as frequency increases and as wavelength
decreases. Highest: x-ray
- Range of Wavelengths - -10^-16 - 10^8 = 24. Only a third are visible
- Black Body Radiation - -When a mass is heated it emits a type of EM
radiation, at very high temps the mass becomes "white hot" because all
wavelengths of visible light become equally intense
- Photoelectric Effect - -Metals emit electrons when electromagnetic
radiation shines on the surface, light is transfers energy to the electrons at
the metal's surface where it's transformed into KE that gives the electrons
enough energy to leave the atom
Depends on frequency not intensity
- How many electrons are emitted if the light is below it's threshold
frequency no matter the intensity? - -None.
- What increases the number of electrons to be emitted by the photoelectric
effect? - -Intensity.
- A particle that transfers light energy with a definable energy, emits one
electron
energy of = h (6.626 x 10^-34 J) - -Photon.
- Energy of light equation? - -E = hV.
, - h - -Planck's constant, the energy of a photon.
- What happens to the energy when there is a short wavelength? - -High
energy.
- Light from the sun (white light) can be separated by a prism to create this,
only a small part of the full EM spectrum? - -Visible Spectrum.
- Atomic Emission Spectrum - -Spectrum that emits photons, energy
diagram: electron goes down energy levels.
- Atomic Absorption Spectrum - -Spectrum that absorbs photons, energy
diagram: electrons goes up in energy levels.
- Heisenberg Uncertainty Principle - -Principle states that we can't
accurately measure both the position and the energy of a small particle
(electron)
Bohr's model did - why its wrong.
- Schrodinger's Wave Equation - -Treated electron as waves derived by
mathematical descriptions of energies.
Psi = wave function of an electron
Psi^2 = probability of finding an electron.
- Atomic Orbitals - -Regions of space where electrons with a particular
quantized energy have a high probability of being found, described by
quantum numbers.
- What are the quantum numbers? - -n, l, ml, and ms.
- What does quantum number "n" mean? - -Determines the energy of the
electron and identifies its shell.
- What does quantum number "l" mean? - -Identifies the type of orbital
(s,p,d) and subshell
= 0 - n-1.
- What does quantum number "ml" mean? - -Specifies a particular orbital
within a subshell
= -l - +l (2l + 1 possible values)
tells us how many s,p,d orbitals are found in each sub shell.
- What does quantum number "ms" mean? - -Describes the spin of the
electron in each orbital
= +1/2 or -1/2
Accurate Q’s and A’s
Lights acts as what? - -Particle and wave.
- Wavelength - -The distance (m) of waves from peak to peak. Short: x-ray
(red), long: infrared (blue)
Short - higher energy
Long - lower energy
- Frequency (V) - -The number of wavefronts per second. Highest: x-ray
- Velocity of Light - -C = 3.00 X 10^8
= wavelength X frequency
- Amplitude - -The intensity, height of peaks of waves. Highest: blue light
- Energy of Wave (J) - -Increases as frequency increases and as wavelength
decreases. Highest: x-ray
- Range of Wavelengths - -10^-16 - 10^8 = 24. Only a third are visible
- Black Body Radiation - -When a mass is heated it emits a type of EM
radiation, at very high temps the mass becomes "white hot" because all
wavelengths of visible light become equally intense
- Photoelectric Effect - -Metals emit electrons when electromagnetic
radiation shines on the surface, light is transfers energy to the electrons at
the metal's surface where it's transformed into KE that gives the electrons
enough energy to leave the atom
Depends on frequency not intensity
- How many electrons are emitted if the light is below it's threshold
frequency no matter the intensity? - -None.
- What increases the number of electrons to be emitted by the photoelectric
effect? - -Intensity.
- A particle that transfers light energy with a definable energy, emits one
electron
energy of = h (6.626 x 10^-34 J) - -Photon.
- Energy of light equation? - -E = hV.
, - h - -Planck's constant, the energy of a photon.
- What happens to the energy when there is a short wavelength? - -High
energy.
- Light from the sun (white light) can be separated by a prism to create this,
only a small part of the full EM spectrum? - -Visible Spectrum.
- Atomic Emission Spectrum - -Spectrum that emits photons, energy
diagram: electron goes down energy levels.
- Atomic Absorption Spectrum - -Spectrum that absorbs photons, energy
diagram: electrons goes up in energy levels.
- Heisenberg Uncertainty Principle - -Principle states that we can't
accurately measure both the position and the energy of a small particle
(electron)
Bohr's model did - why its wrong.
- Schrodinger's Wave Equation - -Treated electron as waves derived by
mathematical descriptions of energies.
Psi = wave function of an electron
Psi^2 = probability of finding an electron.
- Atomic Orbitals - -Regions of space where electrons with a particular
quantized energy have a high probability of being found, described by
quantum numbers.
- What are the quantum numbers? - -n, l, ml, and ms.
- What does quantum number "n" mean? - -Determines the energy of the
electron and identifies its shell.
- What does quantum number "l" mean? - -Identifies the type of orbital
(s,p,d) and subshell
= 0 - n-1.
- What does quantum number "ml" mean? - -Specifies a particular orbital
within a subshell
= -l - +l (2l + 1 possible values)
tells us how many s,p,d orbitals are found in each sub shell.
- What does quantum number "ms" mean? - -Describes the spin of the
electron in each orbital
= +1/2 or -1/2
