Ch 26 Flashcards
Intramolecular bonds hold
Atoms together as molecules
Intramolecular bonds include
Covalent and ionic bonds
Lithium bonds to form how many valence electrons
Two
Beryllium bonds to form how many valence electrons
Four
Boron bonds to form how many valence electrons
Six
Elements beyond the second row can
Expand octets to include more than eight electrons
Ionic compounds form crystal lattices consisting of
Arrays of positive and negative ions
Ionic compounds have high melting and boiling points due to
Strong electrostatic forces between the ions
Ions can conduct electricity in what state?
Liquid / aqueous
Covalent bonds have low melting points and can’t
Conduct electricity in the liquid or aqueous states
What features characterize covalent bonds?
Bond length and bond energy
What is bond order?
The number of shared electron pairs between two atoms
What is the average distance between the two nuclei of atoms in a bond
Bond length
A triple bond is shorter than
Double bond
A double bond is shorter than
Single bond
Bond energy is the energy
Required to separate two bonded atoms
The strength of a bond (and bond energy) increases as the
Number of shared electron pairs increases
H has how many valence electrons
1
C has how many valence electrons
4
N has how many valences electrons
5
What atoms usually are the end electrons?
H, F, Cl, Br, I
What is the equation for formal charge?
V - (number of dots + number of sticks)
Formal charges are used to
Assess stability of particular resonance structure
A stable Lewis structure consists of
Negative charges on most electronegative atoms
Atoms found in or beyond the third period can have
More than eight valence electrons
Atoms found in or beyond the third period can be assigned
More than four bonds
The nature of a covalent bond depends on
The relative electronegativities of atoms sharing electron pairs
Nonpolar covalent bonding occurs between
Same electronegativities
What is a Lewis Acid?
Compound that can accept an electron pair
What is a Lewis Base?
Compound that can donate an electron pair
Tetrahedral structures are usually
Nonpolar
Angular structures are usually
Polar
l describes what within n shells
The orbitals
S orbitals are
Spherically symmetric
P orbitals have what shapes
Dumbbell
Bonding orbitals are formed when
Two atomic orbitals are in phase
Antibonding orbitals are formed when
Two atomic orbitals are not in phase
What bonds are formed when two orbitals of different atoms overlap head-to-head
Sigma bonds
What bonds are formed when two p parallel orbitals interact
Pi bonds
Rate strength of: Dipole-ion Dipole-dipole Hydrogen Bonds London Forces
Dipole-ion > HB > dipole-diple > London Forces
