Week 2 Molecular Orbitals, Covalent Solids Flashcards
what are the 4 sub-orbitals in a p-orbital
σ, σ, π, π
in what order do the p sub orbitals fill up
σ, π, σ, π
what do the p sub orbitals correspond to
the π corresponds to the px,py orbitals
the σ corresponds to the pz orbitals
what allows for hybridisation in molecular orbitals
the closeness in energy of the sub orbitals
what does hybridisation do
lowers energy of the lowest hybridised orbital, increases the energy of the highest hybridised orbital
what is the bond order equation
[(number of bonding electrons) - (number of antibonding electrons)] / 2
what are two important properties of the bond order value
if bond order < 0 then the bond is unstable
higher bond order means shorter bond length
what are the three types of excitations in a hydrogen molecule
electronic
vibrational
rotational
what is the electric excitation value roughly
a few eV
what is the vibrational excitation equation and the associated ω equation
En = (n+1/2)ħω ω = SQRT[k/μ]
what are the two rotational energy equations
Erot = J(J+1)ħ^2 / 2I = L^2 / 2I
what are the two excitation energy ratio equations
Ee / Ev = SQRT[mp/me]
Ee / Er = mp/me
define simply covalent bonding
sharing of electrons
what is the density of state eqn
g(E)dE = number of allowed energy levels per unit volume of solid in the energy range E –> E+dE
