Chem133 Chapter7

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Chem133 Chapter7
2013-10-08 19:54:54
Chem Chemistry 133 Chem133 Chemistry133 foust test2

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  1. What is the speed of light (m/s)?
    • The speed at which electromagnetic radiation travels.
    • 3.00x108m/s
  2. What is the symbol and unit for frequency?
    •  =hertz (Hz)
    • 1/s
    • s-1

  3. What is the symbol for wavelength?
  4. Equation for the speed of light (speed of any wave):
    • =c for light
  5. What does the amplitude of an electromagnetic wave correspond to?
    Its intensity, or for visible light- its brightness.
  6. Define refraction.
    • When an object (or light) passes from one medium to another (at an angle other than 90°) its velocity changes, causing a change in direction.
    • Light is a special case, because it continues to move at a constant velocity while in a medium.
  7. What is dispersion?
    When the components of white light refract at different angles, separating them into a spectrum.
  8. What is diffraction?
    When a wave strikes the edge of an object, it bends around it.
  9. What are destructive and constructive interference patterns?
    • Destructive wave patterns occur when the crest of one wave collides with the trough of another- causing a net loss of amplitude.
    • Constructive wave patterns are the opposite; crests add to crests, while troughs add to troughs causing a gain of amplitude.
    • Dude.
  10. What is Planck's equation?
    • E= energy of radiation
    • n= positive integer (1,2,3...) called a quantum number
    • =frequency
    • h= Planck's constant: 
  11. What is a quantum?
    • a definite amount of energy
  12. What is the threshold frequency?
    For light to cause current to flow on a metal, the light must have a minimum frequency.
  13. What's a photon?
    A tiny bundle of energy (a "particle" of light.)
  14. What happens when light from an electrically excited gas is refracted by a prism?
    It creates a line spectrum, or a series of fine lines at specific frequencies separated by black spaces.
  15. What is the Rydberg Equation?
    • Where R=1.096776x107m-1
    • n2>n& Both are integers
    • It predicts the wavelength of the line, and for visible light n1 is 2
  16. What is Bohr's equation?
    • Z is the charge of the nucleus
    • n is the stationary state with 1= ground state.
  17. Define emission spectrum.
    Atoms in an excited state emit photons characteristic of the element as they return to lower energy states producing bright lines against a dark background.
  18. Define an absorption spectrum.
    atoms absorb photons of certain wavelengths and become excited from lower to higher energy states producing black lines against a bright background.
  19. What is the equation to find the de Broglie wavelength?
    • u-speed of object
    • m-mass of object
  20. What is wave-particle duality?
    • The dual character of energy and matter:
    • Energy and matter both possess wave and particle like behavior.
  21. What is the Heisenberg uncertainty principle?
    • The more certain we are of an object's position, the less certain we are of its velocity, and vice versa.
  22. What is the difference between an orbit and an orbital?
    An orbit is an actual path, whereas an orbital is a mathematical function that describes the electrons matter-wave, but has no physical meaning.
  23. How do you specify an atomic orbital?
    • With three quantum numbers:
    • principle quantum number (n)- size {0,1,2,3...}
    • angular momentum quantum number (l)- shape
    • magnetic quantum number (ml)- orientation 
  24. Describe the shapes of the orbitals.
    • s- Spherical
    • p- Dumbell
    • d- 4 "clover shaped orbitals" 1 with 2 lobes and a doughnut shape between them.