Chapter 6: Chemical Bonding


Terms in this set (...)

chemical bond
a mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together
ionic bond
a chemical bond that results from the electrical attraction between cations and anions
covalent bond
results from the sharing of electron pairs between two atoms
an uneven distribution of charge
nonpolar bond
this type of bond is when the bonding electrons are shared equally by the bonded atoms, resulting in a balanced distribution of electrical charge
polar bond
have an unequal attraction for the shared electrons
a neutral group of atoms that are held together by covalent bonds
molecular compound
a chemical compound whose simplest units are molecules
chemical formula
indicates the relative numbers of atoms of each kind in a chemical compound by using atomic symbols and numerical subscripts
molecular formula
shows the types and numbers of atoms combined in a single molecule of a molecular compound
bond length
the distance between two bonded atoms at their minimum potential energy
bond energy
the energy required to break a chemical bond and form neutral isolated atoms
bond length & stability
shorter bond length - more stable the bond
further - unstable
octet rule
chemical compounds tend to form so that each atom, by gaining, losing, or sharing electrons, has an octet of electrons in its highest energy level
exceptions to the Octet Rule
Hydrogen forms bonds in which it is surrounded only by two electrons
Boron has just three valence electrons, so it tends to form bonds in which it is surrounded by six electrons
main group elements in period 3 and up can form bonds more than eight electrons ////
(I mean the only thing you probably need to know here is that Boron is an exception to the octet rule and can only bond 3 times)
Lewis Structures
the pair of dots representing a shared pair of electrons in a covalent bond is often replaced by a long dash
formula unit
the simplest collection of atoms from which an ionic compound's formula can be established
crystal lattice
in an ionic crystal, ions minimize their potential energy by combining in an orderly arrangement known as a
polyatomic ions
a charged group of covalently bonded atoms
the ability of a substance to be hammered or beaten into thin sheets
the ability of a substance to be drawn, pulled, or extruded through a small opening to produce a wire
valence electrons
the electrons involved in the formation of a chemical bond
metallic bonding
the chemical bonding that results from the attraction between metal atoms and the surrounding sea of electrons
valence shell electron pair repulsion
states that repulsion between the sets of valence level electrons surrounding an atom causes these sets to be oriented as far apart as possible
# of atoms: 3 ///// straight line
# of atoms: 3 ///// electrons in the central atom pull the central atom up
trigonal planar
# of atoms: 4 //// no pulling of electrons (hint: BORON)
trigonal pyramidal
# of atoms: 4 /// electrons in the central atom pull the central atom up to make a pyramid shape
# of atoms: 5
the mixing of two or more atomic orbitals of similar energies on the same atom to produce new hybrid atomic orbitals of equal energies
because of their uneven charge distribution, polar molecules have ____. a _______ is created by equal but opposite charges that are separated by a short distance.
higher electronegativity
lower electronegativity
A chemical bond between atoms results from the attraction between the valence electrons and the ________ of different atoms
a shared electron pair
A covalent bond consists of
nonpolar covalent
If two covalently bonded atoms are identical, the bond is identified as
A covalent bond in which there is an unequal attraction for the shared electrons is
high electronegativity
Atoms with a strong attraction for electrons they share with another atom exhibit
ionic character
The greater the electronegativity difference between two atoms bonded together, the greater the bond's percentage of
Ionic bonds form as a result of the electrostatic attraction between
two electrons
A single covalent bond involves the sharing of
resonance structure
structures that cannot be correctly represented by a single Lewis structure; compound drawn differently but yet the same structure
If two covalently bonded atoms move closer than a distance of the bond length, the potential energy of the atoms
two atoms share two pairs of electrons
In a double covalent bond,
lattice energy
What type of energy best represents the strength of an ionic bond?
formula unit
negative ions
In a crystal of an ionic compound, each cation is surrounded by a number of
molecules in a molecular compound are generally _______ than the attractive forces among formula units in ionic bonding
lower in potential energy
compared with the neutral atoms involved in the formation of an ionic compound, the crystal lattice that results is
lacks molecules
An ionic compound is not represented by a molecular formula because an ionic compound
lattice energy
The energy released when one mole of an ionic crystalline solid is formed form ions in the gas state is known as
decrease; more stable arrangements
As atoms bond with each other, they _____ their potential energy, thus creating _________ arrangements of water
Bond length is the average distance between two bonded atoms at which potential energy is at a
strength of an ionic bond
the lattice energy is a measure of the
metallic bond
A chemical bond formed by the attraction between positive ions and surrounding mobile electrons is a
allow one plane of ions to slide past another
Metals are malleable because the metallic bonding
VSEPR theory
The concept that electrostatic repulsion between electron pairs surrounding an atom causes these pairs to be separated as far as possible is the foundation of
the equal but opposite charges present in the two regions of a polar molecule create a
shared by all surrounding atoms
In metals, the valence electrons are considered to be
chemical bonds
The fact that metals are malleable and ionic crystals are brittle is best explained in terms of their
absorb and re-emit the light
As light strikes the surface of a metal, the electrons in the electron sea
In general, the strength of the metallic bond _____ moving from left to right on any row of the periodic table
do not break
When a metal is drawn into a wire, the metallic bonds
a sea of free moving electrons
the arrangement of valence electrons in a metallic bond is best described as
valence electrons
The electrons involved in the formation of a chemical bond are called?
nonpolar covalent
if 2 covalently bonded atoms are identical the bond is
ionic character
the greater the electronegativity difference between 2 bonded atoms, the greater the percentage of _____ in thebond
The electron configuration of nitrogen is 1s2, 2s2, 2p3 How many more electrons does nitrogen need to satisfy the octet rule?
least electronegative atom
In drawing a lewis structure, the central atom is generally the
nonpolar covalent bond
The lewis structure for the ammonium ion, NH4 has
electron sea
in metallicbonds, the mobile electrons surrounding the positive ions are
regions of positive/negative charge
a polar molecule contains
dipole is induced
when a polar molecule attracts the electron in a nonpolar molecule