Chapter 2 - Molecules Flashcards
Valence bond theory
treats the formation of a molecule as arising from the bringing together of complete atoms which, when they interact, to a large extent retain their original character.
Molecular orbital theory
allocates electrons to molecular orbitals formed by the overlap (interaction) of atomic orbitals.
Van der Waals forces include
dispersion and dipole-dipole interactions.
Van der Waals forces operate ________ molecules.
between
Van der Waals radius
Half the distance of closest approach of two non-bonded atoms of the same element.
Valence bond theory considers
the interactions between separate atoms as they are brought together to form molecules.
Diamagnetic species
All electrons are spin-paired; a diamagnetic substance is repelled by a magnetic field.
Paramagnetic species
Contains one ore more unpaired electrons; a paramagnetic substance is attracted by a magnetic field.
The number of molecular orbitals that can be formed must equal
the number of atomic orbitals of the constituent atoms.
Bond order
= 1/2 (bonding electrons - antibonding electrons)
The lower the bond order, the _________ the internuclear separation.
larger
A basis set of orbitals
is composed of those which are available for orbital interactions.
Isoelectronic species
Two species are isoelectronic if they possess the same total number of electrons.
Hypervalent species
Atoms that contain more than 8 valence electrons.
1 Debye (D) =
= 3.336 x 10^-30 Cm
