CHEM 121 FINAL EXAM | UPDATED QUESTIONS AND
ANSWERS UPDATED .Buy Quality Materials!
ionic bonds
the electrostatic forces that hold ions together in ionic compounds
groups 1 and 2 in a compound mean ionicc
cant have an expanded octet
hydrogen, helium, li
thium to neon
can have expanded octet
aluminum and down can have an expanded octet
odd number of electron =
radical
isolable
capable of being isolated
covalent bonds
Bonds created by sharing electrons with other atoms.
steps for lewis struture
steps for oxidation state
metallic bonds
the force of attraction that holds metals together; it consists of the attraction of free-
floating valence electrons for positively charged metal ions
electronegativity
A measure of the ability of an atom in a chemical compound to attract electrons
electronegativity trend
increases across a period, decreases down a group
homonuclear diatomic molecules
diatomic molecules containing atoms of the same elements
Hetronuclear Diatomic Molecules
which bonds are most polar
the ones that have a greatest difference in electronegativity
shielding effect
the reduction of the attractive force between a nucleus and its outer electrons due to the
blocking effect of inner electrons
redox reaction
A chemical reaction involving the transfer of one or more electrons from one reactant to
another; also called oxidation-reduction reaction.
reduction
gain of electrons
oxidation
loss of electrons
bond order
the number of bonds between atoms: 1 for a single bond, 2 for a double bond, and 3 for
a triple bond
bond length
, the average distance between the nuclei of two bonded atoms
bond dissociation energy
the energy required to break the bond between two covalently bonded atoms
single bond length
longest
double bond length
medium
triple bond length
shortest
polar covalent bond
A covalent bond in which electrons are not shared equally
bond dipole
separation of electrical charge created when atoms with different electronegativities
form a covalent bond
percent ionic character of a bond
a measure of how the actual charge separation (partial charge) in a bond because of
electronegativity difference of the bonded atoms compares to the complete charge
separation associated with ions
Electron Dificient
incomplete octet
hypervalent
molecules and ions with more than an octet of electrons around the central atom
octet rule
8 electrons in the valence shell
free radicals
chemical particles with an odd number of electrons
exceptions to octet rule
in third period and later period of p block have more than 8 electrons sometimes
formal charge
# of valence electrons - ( # dots + # lines)
steps for lewis diagrams
resonance structures
structures that occur when it is possible to draw two or more valid electron dot
structures that have the same number of electron pairs for a molecule or ion
weight of resonance structures
average of the set of structures
best resonance structure
formal charge is smaller, negative formal charges are on the more electronegative
atoms, like charges should not be on adjacent atoms
Chemically reasonable resonance structure
formal charges are small not minimized
resonance hybrid structure
dont draw these
isomers
Two different molecules that have the same chemical formula
rule
ANSWERS UPDATED .Buy Quality Materials!
ionic bonds
the electrostatic forces that hold ions together in ionic compounds
groups 1 and 2 in a compound mean ionicc
cant have an expanded octet
hydrogen, helium, li
thium to neon
can have expanded octet
aluminum and down can have an expanded octet
odd number of electron =
radical
isolable
capable of being isolated
covalent bonds
Bonds created by sharing electrons with other atoms.
steps for lewis struture
steps for oxidation state
metallic bonds
the force of attraction that holds metals together; it consists of the attraction of free-
floating valence electrons for positively charged metal ions
electronegativity
A measure of the ability of an atom in a chemical compound to attract electrons
electronegativity trend
increases across a period, decreases down a group
homonuclear diatomic molecules
diatomic molecules containing atoms of the same elements
Hetronuclear Diatomic Molecules
which bonds are most polar
the ones that have a greatest difference in electronegativity
shielding effect
the reduction of the attractive force between a nucleus and its outer electrons due to the
blocking effect of inner electrons
redox reaction
A chemical reaction involving the transfer of one or more electrons from one reactant to
another; also called oxidation-reduction reaction.
reduction
gain of electrons
oxidation
loss of electrons
bond order
the number of bonds between atoms: 1 for a single bond, 2 for a double bond, and 3 for
a triple bond
bond length
, the average distance between the nuclei of two bonded atoms
bond dissociation energy
the energy required to break the bond between two covalently bonded atoms
single bond length
longest
double bond length
medium
triple bond length
shortest
polar covalent bond
A covalent bond in which electrons are not shared equally
bond dipole
separation of electrical charge created when atoms with different electronegativities
form a covalent bond
percent ionic character of a bond
a measure of how the actual charge separation (partial charge) in a bond because of
electronegativity difference of the bonded atoms compares to the complete charge
separation associated with ions
Electron Dificient
incomplete octet
hypervalent
molecules and ions with more than an octet of electrons around the central atom
octet rule
8 electrons in the valence shell
free radicals
chemical particles with an odd number of electrons
exceptions to octet rule
in third period and later period of p block have more than 8 electrons sometimes
formal charge
# of valence electrons - ( # dots + # lines)
steps for lewis diagrams
resonance structures
structures that occur when it is possible to draw two or more valid electron dot
structures that have the same number of electron pairs for a molecule or ion
weight of resonance structures
average of the set of structures
best resonance structure
formal charge is smaller, negative formal charges are on the more electronegative
atoms, like charges should not be on adjacent atoms
Chemically reasonable resonance structure
formal charges are small not minimized
resonance hybrid structure
dont draw these
isomers
Two different molecules that have the same chemical formula
rule
