Lab 5-Molecular Geometries Flashcards
The octet rule
Atoms often gain, lose, or share electrons to achieve the same number of electrons as the noble gas closest to them. There are many exeptions
Electrostatic forces
Maintain the ions in a rigid, well defined, three-dimensional arrangement. Many solids are pliable
Simplest covalent bond
H2
Covalent bonding of attraction and repulsion
The two positively charged nuclei and the two negatively charged electrons repel each other, whereas the nuclei and electrons are attracted to one another.
Electron density location
In between the two bonded atoms as they are attracted to each others nuclei
Atoms obtain octets
By sharing more than one pair of electrons if they need
Steps to draw a Lewis Structure
Sum the valence electrons from all the atoms, write the symbols and how the atoms are connected with single bonds, complete the octet of the outer atoms, put extra electrons on the central atom or multiple bonds.
Formal charge
Is the charge that an atom in a molecule of ion would have if all atoms had the same electronegativity
Formal charge calculation
Done for each atom. subtract the number of electrons assigned to the atom from the number of valence electron in the neutral atom
Preferred formal charge
Zero. The more electronegative the atom, the more formal charge it will have
Polar bonds
Result from a difference in electronegativities
Bond dipole moment
Is a charge separation over a distance u=Qr
Bonding electrons and electronegativity
There is an increased attraction
Polyatomic ion bond dipole
Are the vector sums of the individual bond dipoles
The best electron configuration
Is the one that minimizes they repulsions among them
Coordination number
The same thing as electron domains
Electron domain geometry
The arrangement of electron pairs about the central atom of a ABn molecule, where A is the central atom and B are the peripheral atom
Predicting electron geometry
Sketch the lewis structure, Count the number of electron pairs around the central atom, describe the molecular geometry in terms of angular arrangements
Electron domain geometry multiple bonds
They act as one bonding pair
VSEPR doesn’t
Explain why bonds exist between atoms
Valence bond theory
Build up of electron density between two nuclei is visualized as occurring when a valence atomic orbital of one atom merges with that of another atom
Overlapping of orbitals
Allows two electrons of opposite spin to share the common space
Hybridization
A procedure of mixing two or more atomic orbitals on an atom
