Jake Gold
Eddy Yokana
Unit 6: Quantum Mechanics, molecular structure, and orbital theory
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Lewis Structures- remembers that extra electrons go in D orbitals and if not enough electrons
than it probably has double or triple bonds.
Polarity- a bond is polar if electronegativity difference is greater than 0.5. Fluorine is polar with
everything; oxygen is polar with everything except chlorine. A polar molecule must have polar
bonds that are asymmetrical.
Molecular structures of increasing electrons- linear, trigonal planar, tetrahedral, trigonal
bipyramidal, octahedral. All of these are naturally symmetrical. Angles: 120° for trigonal planer
and trigonal bipyramid (only for electrons that form an equilateral triangle). 109° for bent,
tetrahedral. 90° for trigonal bipyramidal and octahedral (only for certain electrons).
The wavelengths for visible light are 380nm-740nm, and remember ROYGBIV.
Quantum numbers: N is principle identifies the electron shell (0,1,2…,7 ), l is angular momentum
describes the subshell (s, p, d, f are 0, 1, 2, 3 respectively), ml describes the orbital within the
subshell (For d’s subshell -2,-1,0,1,2)
Periodic trends such as: bond strengths, ionization energy, electron negativity, orbital size
Electron configuration
Sigma vs. Pi bonds (sigma bonds are single bonds and Pi are double or triple bonds)
Formal charges-Number of valence electrons – number of non-bonding electrons (bonding
electrons count as half). If multiple isomers, the molecule with the least formal charges is
favored.
Standard homonuclear molecular orbital diagram (know bond order, net sigma/pi bonds,
highest energy molecular orbital)
Paramagnetic- Paramagnetic material is only attracted when in the presence of an externally
applied magnetic field. A molecule is paramagnetic if it has unpaired electrons in its valence
shell in ground state.
Diamagnetic- Diamagnetic material creates a magnetic field in opposition to an externally
applied magnetic field. A molecule is diamagnetic if it only has paired electrons in its valance
shell in ground state.
Coordinated covalent bonds- Is a kind of covalent bond in which both electrons of derived from
the same atom. This bond usually forms from Lewis acids and Lewis bases.
Adduct-A molecule that has a coordinated covalent bond is called adduct.
Resonance structures- A molecule or ion that contains a delocalized electron, where a bond
cannot be described by one single bond. Use formal charges to find which is most stable.
Equations
E=hf
KE= 1/2 mv2
C=fλ
C=2.9979 x 109 m/s
h= 6.626 x 10.34 J S
Me= 9.11 x 10-31 kg
h
mv
NA= 6.022 x 1023
λ=
KEmax= Ephoton-Ethreshold
W= energy threshold