light and atoms Flashcards
(43 cards)
what creates an electromagnetic wave
the oscillation of an electron
roughly show the visible light spectrum and the colors associated with there frequency
draw the wave diagram of a vertical and horizontally positioned antenna with axis labels
what is the definition of monochromatic light
mono chromatic light is light composed of a single frequency
what is a coherent wave source
a coherent wave source is a wave source that is in phase and has the same frequency
why is white light neither monochromatic or coherent
because white light is made up of lots of different colors of light it isn’t monochromatic and these are out of phase therefore not coherent
what is required to have a good observable diffraction effect
the wavelength must be similar to the slit size
what is required to have a good observable diffraction effect
the wavelength must be similar to the slit size
what is diffraction
diffraction is the bending of a wave as it passes through an opening or around an obstacle
what does an intensity distribution of a diffraction grating glook like
what formula would you use to find the maximum orders for a diffraction grating
what is the photoelectric effect
the photoelectric effect is the emission of electrons when illuminated by light of high enough frequency
what effect does increasing the intensity but not the frequency have on the readings
there is a higher current detected
what effect does increasing the frequency have on the readings
when the frequency is increased the kinetic energy is increased
how did Einstein explain the photo electric effect
draw a graph of ek max vs frequency label and explain all the intercepts and the slope and what happens if a metal with a higher threshold frequency is measured
the slope would be equal to planks constant
how does an x-ray differ from a standard photoelectric effect
-they have a continuous range of frequency’s
-an x-ray is caused by accelerating an electron not a photon
-there are high intensity peaks at certain frequencies
why does an x-ray have a continuous range of frequency’s
when an electron collides closer to the nucleus there is more energy as the path is changed by the electrostatic forces and the closer to the nucleus the more energy
draw a graph and explain what happens to a intensity vs frequency graph for an x-ray when the current is increased, the voltage is increased or the target metal is changed
what is attenuation
attenuation is the reduction in x-rays as they pass through a material due to the absorption or scattering of x-ray photons
what can effect attenuation
-the thicker a material is the greater the attenuation
-the denser the material the less x-rays can pass through
-the greater the atomic number of a material the greater the attenuation
what is the diffrence between hard and soft x-rays
a hard x-ray is used when doing things like chest or leg x-rays and have high photon energies and frequency’s
soft x-rays are used on things with low attenuation and will have relatively low photon energies and frequency’s
what was de Broglie’s proposal
de Broglie proposed that moving particles have a wavelength that depends on there momentum
what is the formula for de Broglie’s wave length
lambda= h/p