Structure & Bonding Flashcards
What is a node?
A locus where the wave function crosses zero
Valence Bond Theory
Bonding electron pairs are localised between atoms
Molecular Orbital Theory
Molecular orbitals are spread out or delocalised over the molecule
Isoelectronic
same number of electrons
pm to m
1pm = 10 -12 m
What were the first assumptions of the bohr model of the H atom?
1) The electrons move in circular orbit around nucleus
2) Only certain discreet orbits are allowed and e- don’t emit radiation when in the orbits
3) When an e- moves from one orbit to another, a single photon is emitted or absorbed
Å to m conversion
1 Å = 10 -10 m
What is Ψ 2 ?
the probability of finding the e- at that point
What are special about eigenfunctions (allowed wavefunctions)?
wavefunctions corresponding to different energies are orthogonal (the integral of their product is 0)
If Ψ is a complex number, how do you find the probability of finding the electron at that point?
multiply by its complex conjugate
Define the quantum numbers
n = principal q.n. (size)
l = orbital angular momentum q.n. (shape)
m l = magnetic q.n. (oritentation)
How many nodes does each energy level have?
ns has n-1 radial nodes
np has n-2 radial nodes
nd has n-3 radial nodes
nf had n-4 radial nodes
Result of diamagnetism
weak repulsion due to the pairing of all electrons
Explain the formation and purpose of hybrid orbitals and its application to chemical bonding
Hybridisation occurs to generate orbitals which are more directional and give better overlap. It provides a model where carbon can form 4 bonds from two singly occupied orbitals
Electron shielding
the blocking of valence shell electron attraction by the nucleus due to the presence of inner shell electrons
