Unit 6: Electron Structure in Atoms Flashcards
True or false.
light is a wave
TRUE
Definition of electromagnetic radiation
carries energy through space
- creates electromagnetic fields
- creates the electromagnetic spectrum
What is the equation to find either wavelength or frequency?
c = λ * V
v=frequency
λ= wavelength
C= speed of light 3.0 x 10^8 m/s
Definition of wavelength
The distance between two points (crest or trough) on a wave
Definition of amplitude
The distance from a crest or trough to the middle line
Definition of frequency
The number of cycles that pass a point per second
How is frequency measure?
measured in cycles/second or S-1 or Hertz (Hz)
Horizontal rows on the periodic table are….?
periods
What does the periods mean?
n= outermost energy level that is occupied with electrons
Definition of black-body radiation
The emission of light from hot substances
- The wavelength of light depends on the temp
- red hot substances are cooler than white hot substances
Who is Max Planck?
- German physicist
- assumed that energy can be released by atoms only in discrete “chunks” of some minimum size.
- atoms cant cont. emit or absorb energy
- BUNDLES OF ENERGY
Definition of quantum
The smallest quantity of energy that can be emitted or absorbed as electromagnetic radiation
What is the equation to find the energy of a single quantum? E=….
E = hv h= planck's constant v= frequency
What is planck’s constant?
6.63X10^-34 J*s
What is planck’s quantum theory?
energy is always emitted or absorbed in whole number multiples of hv
What is photon emission?
This is when light is given off and and electron falls down to a lower energy level
What is photo absorption?
This is when light hits an atom and makes an electron jump to a higher energy level
What is the photoelectric effect?
Light of a certain frequency causes atoms on the surface to emit electrons
What did albert einstein come to the conclusion when he put together planck and applied it to the photoelectric effect?
Energy hitting the metal is a stream of tiny energy packets
- energy of photon is proportional to the frequency
- E (energy of photon) = hv
Fill in
____ light frequency= _____ energy photons = ____ to eject electrons
____ light intensity = ____ electrons ejected from atoms
____ light frequency (v) = ____ speed of electrons ejected from atoms
- Higher, higher, easier
- higher, more,
- Higher, faster
Definition of spectrum?
produced when radiation of various wavelengths is separated (light bulbs, stars)
Definition of continuous spectrum?
contains all wavelengths of light (rainbow)
Definition of monochromatic?
having only one wavelength of light (laser)
Definition of line spectrum?
a spectrum containing radiation only of certain wavelengths
What are Bohr’s 2 major ideas?
- electrons exist only in discrete energy levels; quantum numbers
- energy is involved in moving an electron from one level to the next
What did Louis de Broglie think of?
an electron behaves like a wave as it moves around the nucleus and has a specific wavelength - Matter Wave
*the λ of the electron depends on its mass and velocity (called momentum)
What is an equation to find λ?
λ = h / mv
h=planck’s constant
m=mass
v=velocity
What is the Heisenberg uncertainty principle?
impossible to know exactly where an electron is around the atom
What did Erwin Shrodinger come up with?
Developed the wave equation proposal
- developed wave functions that describe the electrons matter wave
- the location of electrons is based on these and probability
What do orbitals look like and what three ideas go wiith them?
look like clouds
- have diff shapes
- have diff energies
- orbitals are diff than orbits (which are simple circles)
What are the 3 quantum #’s in the quantum mechanical model?
- principal quantum number
- azimuthal quantum number
- magnetic quantum number
What is the principal quantum number?
n=1, 2, 3, etc
- gives the level of the orbital
- as n increases the orbital becomes larger
- as n increases the electron has more energy and is less tightly bound to the nucleus
- shell=orbit=energy level
What is the azimuthal quantum number?
ℓ = 0 to n-1
*defines shape
s, p, d, f
*orbital=subshell
ℓ = 0, orbital letter s, shape= spherical
ℓ = 1, orbital letter p, shape principal (infinity sign)
ℓ = 2, orbital letter d, shape diffuse (four leaf clover)
ℓ = 3, orbital letter f, shape fundamental (crazy shape dont need to know)
What is the magnetic quantum number?
mℓ = symbol
- values of ℓ to -ℓ (including 0)
- defines the orientation in space (x,y,z)
What do the 3 numbers for the quantum mechanical model?
probable location of an electron
What is the 4th quantum number?
Ms = the spin magnetic quantum number
- indicates what direction the electron spins
- 2 values +1/2 or -1/2
Definition of Aufbau principle?
electrons enter orbitals with the lowest energy first. this means that electrons must fill the first energy first level before placing any in the second
Definition of Pauli exclusion principle?
each atomic orbital contains a maximum of two electrons.
Definition of Hund’s Rule
Electrons enter each orbital of a given type singly and with identical spins before any pairing of electrons of opposite spin occurs within those orbitals
*each orbital of a certain shape receives one electron before you can double them up
What is the diff between electron configuration and orbital diagram?
the diagram has the arrows and the configuration is just numbers ans letters (ex. 1s^2 2s^2….)
