Chapter 6 Flashcards
What is electromagnetic Radiation?
a form of energy that has wave characteristics and that propagates through a vauum at the speed of 3.00 X 10^8 m/s
What are the different types of waves?
radio waves, infrared radiation, ultraviolet radiation, x-rays
What is the wavelength?
the distance between identical points on sucessive waves
What is the frequency of a wave?
the number of complete wavelenghts, or cycles, that pass a given point
When wavelenght is long is frequency high or low?
low
When wavelenght is short is frequenecy high or low?
high
What is the equation to find wavelenght?
speed of light/frequency
What is the equation to find frequency?
speed of light/ wavelength
Order the different radiations by wavelength(longest to shortes?
radio frequency, microwaves, infrared, visible light ,ultraviolet, x-rays, gamma rays
Order the different radiations by frequency(highest to lowest)
Gamma rays, x-rays, ultraviolt, infrared, microwaves, radio frequency
Order the visible region by wavelenght(longest to shortes) by color?
red, yellow, green, blue, purple
Order the visble light by highest to lowest(freunecy) color?
purple, blue, green, yellow, red
What is the unit for frequency?
hertz(Hz) or s^-1
How to make nm to m?
times it by 10^-9
What is blackbody radiation?
the emission of light from hot objects
What is photoelelectric effect?
the emission of electrons from metal surfaces on which light shines
What is the emission spectr?
the emission of light from electroncially excited gas atoms
What did planck theorize about energy?
energy cna be either released or absorbed by atoms only in discrete chuncks of some minumum size
What is quantum?
the smallest quanity of energy that can be emitted or absorbed as electromagnetic radiation
How do you find Energy of a phton?
E=hv
What is h in the equation E=hv?
planck constant(6.626 x 10^-34 J-s)
When frequency increases what happnes to the photon energy and the kinetic energy?
photon energy will increase and kinetic energy of the ejected electrrons will increase
What is a photon?
the smallest increment of radiant energy
What happens to the emission of electrons when you increase the intensity light source?
doesn’t lead to emission of electrons
What happens to the emission of electrons when you increase the frequency of the light?
increases the emission of electrons
What happens to the number of photons when the intensity of light is increaseds?
number of photons increase but the energy doesn’t
What happenes to the excess energy of the photon?
it is converted into kinetic energy of the emitted electron
How to find Energy of a photon in J/mol
Times the energy by 6.022 x 10^23
When given the energy of the poton and then the pulse of the photon how do you find what the total energy is?
times the two
How do you find the number of photons emitted when given the energy of something and the energy of the photon?
enery during pulse/radiaton energy
What is monochromatic?
radiation composed of a single wavelenght
What is plychromatic radiation?
produces radiation containing many different wavelenghts
When is a spectrum produced?
when radiation from a polychromatic source is separated into its componet wavelenghts
What is the continous spectrum?
a spectrum that contains radiation distributed over all wavelenghts
What is a line spectrum?
a spectrum that contains radiation at only certain specifc wavelenghts
What is the wavelength of violet?
410nm
What is the wavelength of blue?
434 nm
What is the wavelenght of blue-green?
486nm
what is the wavelength of red?
656nm
What does rydberg equation allow us to calculate?
the wavelenghts of all the spectral lines of hydrogen
What is rydberg equation?
1/wavlenght=(RH(1/n1^2 - 1/n2^2
What is Rh in the rydberg equation?
rydberg constant which is 1.096776 x 10^7 m^-1)
How does bohr explain why an electron doens’t spiral into hydrogen?
only orbits of certain radii, corresponding to certian specific energies, are permitted for the elctron in a hydrogen atom
What an allowed energy state?
an electron permitted to obrit
Why does an electron in a allowed energy state doesn’t spiral into the nucleus?
does not radiate energy
when is an electron emitted or absorbed?
as the electron changes from one allowed energy state to another
What is the n quantum number?
orbits and energy levels
How do you find energy of a electron?
∆E=(-2.18 x10^-18)(1/nf^2-1/ni^2)
What numbers can the n quantum number be?
1,2,3,4… has to be a positive interger
What happens to the radius as n increases?
the radius gets larger
What happens to the stability of an atom as the energy increases?
becomes less stable teh lower(more negative) the energy the more stable
What happens to the energy as n increases?
energy increaes
What is n=1 called?
ground state
When n= something higher than 1 what is it called?
the excited state
How does an electron jump to a higher energy state?
the electron must absorb energy
What happens to the energy when an electron jumps to a lower energy state?
the electron is emitted
When ∆E is positive what must a photon do?
be abosrbed
When ∆E is negative what must a photon do?
be emitted
How do you find wavelength from Energy of a photon?
hc/-∆E
How to go from m to nm?
times it by 10^9
What is the number for the wavelength gamma rays radiation?
10^-11
What is the number for the wavelength of the x-rays radiation?
10^-9
What is the number for the wavelength of the ultraviolet radiation?
10^-7
What is the number for wavelength of infrared rays?
10^-5
What is the number for the wavelenght for the visible light radiation?
10^-4
What is the number for the wavlenght of the microwaves radaition?
10^-3
What is the number for the wavelenght of the radio radaiton?
10^1 and bigger
What did De Broglie suggest about an electron moving about the nucleus?
it behaves like a wave and therefore has a wavlenght
How do you find wavelength for an electron?
wavlenght= h/mv
What is v in de broglie equation?
velocity
What did de broglie equation apply to?
to all matter, any object of mass and velocity
How to go from pico meters to nano meters?
times it by 10^-3
What did heisenberg discover?
uncertainty princple?
What is the uncertainty princple?
it is impossible for us to know both the exact momentum of an electron and its exact location in space
What are wave functions?
a description of an allowed energy state for an electron in the quantum mechanical model of the atom
What is the electron density?
the proabibilty of finding an electron at any particular poting in an atom
As density increases what happens to the probability of find the electron?
increases
As density decreases what happens to teh proabability of finding an electron?
decreases
What are orbitals?
an allowed energy state of an electron in the quantum mechancial model of the atom
What is the shape of the lowest energy orbital?
a spherical shape
What are the three quantum number in the quantum mechanical model?
n, l, ml
What is the l quantum number called?
angular momentum quantum number
How do you find the l quantum number?
values from 0 (n-1)
When l is 0 what letter do you use?
s
When l is 1 what letter do you use?
p
When l is 2 what letter do you use?
d
When l is 3 what letter do you use?
f
How do you find the ml value?
-l and l including zero
What is the ml quantum number called?
magnetic quantum number
What is an electron shell?
a collection of orbitals that have the same value of n
What are subsells?
orbitals that have the same n and l value
What does s orbitals look like?
spheres
What happens to the peaks of the s orbitals as n increases?
gets larger and larger
For an ns orbtial how do you find the number of peaks?
peaks= the n value
How do you find the number of nodes for a s orbital?
nodes= n-1
For an s orbital what happens to the probablity of finding the electron as n increases?
probabaility increases
What kind of shape is the p orbital?
dumbell(two lobes0
How do you find the number of nodes for a p orbital?
nodes= l value
How do the p orbitals differ?
The ml number causes them to change what nodal plane they are on
What happens to the size of the orbital in the p orbitals as n increases?
size increases
What happens to the size of an orbital as n increases in the d orbitals?
size increases
What do the d orbitals look like?
four leaf clovers(four lobes)
How does the d orbitals change?
As the ml value changes it changes where the nodal plane is
What happens to the energy of an orbital as l increases?
increases
What are orbitals with the same energy called?
degenerate
What is an electron spin?
a propert of the electron that makes it behave as though it were a tiny magnet
What is the spin magnetic quantum numer?
associated with the electron spin
What are the two values for the ms quantum number?
+1/2, -1/2
What is the pauli exclusion principle?
no two electrons in an atom may have the same four quantum numbers(n,l,ml,and ms) can be no more than two electrons in any one atomic orbital
What is hund’s rule?
when filling degenarte orbtials, the lowest energy is attained when the number of electrons have the same spin
