Chapter 7 Flashcards
when wavelength is short, what does that mean for frequency?
high frequency
what color has the highest energy?
violet
what color has the lowest energy?
red
what is an example of red light?
radio waves
what is an example of orange light?
microwaves
what is an example of yellow light?
infrared
what colors of light are visable?
green, blue, indigo, violet
what is an example of green light?
ultraviolet
what is an example of blue light?
x-ray
what is an example of violet light?
gamma ray
what is the wavelength?
distance between two maxima
(distance between two wawves)
what is amplitude?
height of each wave
in comparing two lightbulbs, if they each have different amplitudes, what does that do?
each lightbulb will have different brightness
the short amplitude will have dim light
the long amplitude will have bright light
in comparing two lightbulbs, if they each have different amplitudes, what does that do?
each light bulb will have different brightness
the short amplitude will have dim light
the long amplitude will have bright light
what is frequency (v)?
is the number of cycles per unit time
what does low frequency mean for wavelength?
long wavelength
what is the speed of light?
c = 3.00x10^8 m s^-1
what happens when a wave encounters an obstacle or slit?
it bends (or diffracts) around it
what happens when a particle encounters an obstacle or slit?
the particle goes straight through the slit
when light acts as a particle, what is it called?
the photoelectric effect and blackbody radiation
what happens with higher frequencies (such as indigo)?
more electrons will be able to be transferred
what happens when the intensity of the light increases?
more electrons will be transferred
what did albert einstein say about light particles?
light consists of discrete packets called quanta (photons)
what did max planck say about light particles?
energy is directly proportional to the frequency
what is a beam of light?
a stream of photons of the same energy
what is plancks constant?
6.626x10^-34 Js
what does E stand for?
energy of one photon
what is the photoelectric effect?
energy transfer from the light (one photon) to an electron in the metal
in order to eject an electron?
energy of an incoming photon Ei must be equal or greater than the work function in order to eject electron
what does leftover energy turn into?
KE
label the electrons ejected if its positive or negative *electrons ejected
does the energy of the emitted electrons depend on the intensity of the incoming light?
no
what does the energy of one electron depend on?
the energy of one photon
when an atom absorbs energy what does it re-emit as?
light
light emitted by atoms contains how many wavelengths?
several wavelengths
when electrons jump shells, what happens?
they absorb energy
electron is never observed between states, what does that result in?
resulting in the discrete lines the emission spectrum
when an electron falls back to lower energy level, what happens?
light is emitted
what happens when an electron absorbs energy?
the electron is gets excited to an unstable energy level
can the energy of a photon be negative?
no, always positive
transition between levels that are farther apart in energy produce what?
light that is shorter in wavelength
what does the absorption of the shortest wavelength look like?
big distance between shells
what did louis de broglie say about light?
if light has wave-like and particle-like properties, matter (electrons) must be both particle- like and a wave-like
(light has both particle- like and wave-like properties)
how are we waves?
matter is a wave, and everything is made of matter thus atoms and electrons are also waves
what is h?
planck’s constant = 6.626x10^-34 Js
what unit is wavelength in?
m (its lamda)
