Bonding
Unit 5 Page 1
Learning Target:
I will be able to define ionic bond, explain how ionic bonds form ionic compounds, and discuss the characteristics of
ionic bonding.
I can explain how ionic compounds form formula units by transferring valence electrons in ways that make the atoms
more stable.
Criteria for Success:
I can construct electrons dot formulas to illustrate ionic bonds
Introduction to Bonding
A. A chemical _________ is a mutual electrical attraction between the _____________ charges in the ____________ and
the _____________ charges in the valence levels of different atoms that binds the atoms together.
B. ___________ tend to form so that each atom, by gaining, losing, or sharing electrons has an __________ of electrons
in its ____________ level.
1. The resulting arrangement of electrons ______________ the overall potential ______________ of the system.
Ionic Bonding
A. The electrical attraction between oppositely charged __________ is called an _______________ bond.
1. An ion is an atom in which the total number of electrons is ___________ equal to the total number of protons,
giving the atom a net __________________ or net __________________ charge.
2. An atom that loses an electron(s) to form a positive ion is called a _____________. ______________ typically
lose electrons.
3. An atom that gains an electron(s) to form a negative ion is called an ____________. _____________ typically
gain electrons.
4. Ionic bonds form between both ________________ and __________________ ions.
a. A monatomic ion is an ion consisting of a single ____________________.
b. A polyatomic ion is a charged chemical ion composed of two or more bonded atoms that can be
considered to be acting as a ________________ unit.
5. The ions in ionic compounds exist in a ratio so that the overall charge of compound is ___________________.
A ______________________ _______________ represents the smallest ratio of ions that gives an overall
____________________ charge.
Characteristics of Ionic Bonding
A. The ions in an ionic compound arrange themselves in such a fashion so as to _______________ their potential energy.
This arrangement is described as a ________________ ___________________.
B. Ionic compounds have relatively ______________ melting points and boiling points.
C. Ionic compounds are ________________ and _________________.
D. Many ionic compounds conduct ____________________ when in ___________________ solutions.
Bonding
Unit 5 Page 2
Learning Target:
I can name ionic compounds containing main group or transition metals using International Union of Pure and Applied
Chemistry (IUPAC) nomenclature rules.
Criteria for Success:
I can write the chemical formulas and chemical names of common polyatomic ions, ionic compounds containing main
group or transition metals.
Notes: Chemical Names and Formulas for Ionic Compounds (IUPAC rules)
Monatomic Ions
A. Monatomic ions are charged atoms that form from a ________________ atom.
Naming Monatomic Ions
1. Monatomic _______________ are named simply by the element’s name.
2. Monatomic ________________ are named by changing the ending of the element’s name to __________.
Binary Ionic Compounds
A. Compounds composed of __________ different ions, a cation and an anion, are known as ______________ ionic
compounds. Despite being made of ions, the overall charge of the compound is _______________________.
Steps to Determine the Formula of a Binary Ionic Compound
1. Write the symbols of the ions side by side. Write the ______________ first.
2. Cross over the charges by using the ________________ value of each ion’s charge as the
_____________________ for the other ion.
3. Check the __________________ and divide them by their largest common factor to give the smallest possible
whole-number _______________ of ions.
4. Write the final formula WITHOUT __________________. This represents one ________________ of the ionic
compound.
Example 1: magnesium chloride
Example 2: magnesium oxide
Steps to Determine the Name of a Binary Ionic Compound
1. Write the name of the _______________ first.
2. Write the name of the ______________ second.
Example 1: NaCl
Example 2: Li3N
The Stock System of Nomenclature
A. The Stock System uses a _________________ _________________ to indicate an ion’s charge.
1. A Roman numeral is used when the cation is a _______________________ metal (also Sn & Pb)
a. EXCEPTIONS to this are: _________, __________, __________
Compounds Containing Polyatomic Ions
A. Polyatomic ions are charged ____________________ of covalently bonded atoms.
Naming Ionic Compounds Containing Polyatomic Ions
1. Polyatomic ions have unique names and require ________________.
2. Compounds containing polyatomic ions are named in the _____________ manner as binary ionic compounds.
3. When naming the name of the ______________ is given first, followed by the name of the _______________.
Example 1: KMnO4
Example 2: CaSO4
Example 3: lithium phosphate
Example 4: ammonium nitrate
Hydrated Ionic Compounds
A. Hydrated ionic compounds, __________________, have a specific number of ______________ molecules in their
chemical formula. In the solid, these water molecules are part of the structure of the compound.
1. The waters are separated by a raised _________.
2. The number of water molecules are indicated using a Greek ________________.
Greek prefixes: 1 = ____________
6 = ____________
2 = ____________
7 = ____________
3 = ____________
8 = ____________
4 = ____________
9 = ____________
5 = ____________
10 = ____________
Example 1: copper (II) chloride dihydrate
Example 2: MgSO4•7H2O
Bonding
Unit 5 Page 4
Learning Target:
I will be able to define covalent bond, explain how covalent bonds form covalent compounds, and discuss the
characteristics of covalent bonding.
I can explain how covalent compounds form molecules by sharing valence electrons in ways that make the atoms more
stable.
Criteria for Success:
I can construct electrons dot formulas to illustrate covalent bonds.
Introduction to Bonding
A. A chemical ____________ is a mutual electrical attraction between the ___________ charges in the ______________
and the __________________ charges in the valence levels of different atoms that binds the atoms together.
B. ______________ tend to form so that each atom, by gaining, losing, or sharing electrons has an _______________ of
electrons in its __________________ level.
1. The resulting arrangement of electrons ______________ the overall potential ______________ of the system.
Covalent Bonding
A. __________________ (aka molecular) bonds occur between two __________________ atoms. Electrons are
__________________ to complete the valence levels of the atoms.
1. Nonmetals have ______________ effective nuclear charges (Z eff) and small ____________, so they can attract
and hold each others’ electrons to make shared _______________ of electrons.
2. Atoms can make ________________, ________________, or _______________ bonds depending on whether
they share one, two, or three pairs of electrons respectively.
3. The _________________ group of elements that are held together by covalent bonds is called a
____________________. Covalent compounds are also referred to as ____________________ compounds.
Properties of Covalent Bonding
A. Covalent compounds have relatively __________ melting points.
B. Covalent compounds typically do _______ conduct electrical current when dissolved in ________________ solutions.
C. The distance between two, covalently bonded atoms at their minimum potential energy, that is, that is the average
distance between two bonded atoms, is the _____________ ________________.
1. Generally, ____________________<______________________<____________________.
D. ____________ ________________ is the energy required to break a chemical bond and form neutral, isolated atoms.
Typically represented in ________________ ________ ___________ (kJ/mol).
1. Generally, _____________________<_______________________<_____________________.
Bonding
Unit 5 Page 5
Learning Target:
I can name covalent compounds using International Union of Pure and Applied Chemistry (IUPAC) nomenclature rules.
Criteria for Success:
I can write the formula of a binary covalent compound given its name or write the binary covalent compound from its
formula.
Nomenclature of Covalent Compounds
A. Covalent compounds are named by adding ____________ to the element names.
1. The compounds named in this way are ____________ covalent compounds.
a. ‘Binary’ means that only ______ types of atoms are present.
b. ‘Covalent’ (in this context) means both elements are ___________.
2. A ________ is added to the name of the first element in the formula if more than one atom of it is present.
(The less electronegative element is typically written first.)
3. A ________ is always added to the name of the ___________ element in the formula. The second element will
use the form of its name ending in ‘ide’.
B. When writing formulas of covalent compounds use the __________ in the names that indicate the number of atoms of
each element present.
1. If no prefix is present on the name of the first element, there is only ___ atom of that element in the formula
(its subscript will be an “invisible” 1).
2. A prefix will always be present on the name of the second element. The second element will use the form of
its name ending in _____.
Subscript
Prefix
Subscript
1
6
2
7
3
8
4
9
5
10
Prefix
*Drop –a and –o endings before “oxide”
Bonding
Unit 5 Page 6
Learning Target:
I can explain the difference between polar covalent and non-polar covalent bonding.
Criteria for Success:
I can classify a bond as either polar covalent or non-polar covalent based on electronegativity differences.
Polar Covalent and Non-Polar Covalent Bonding
A. ________________ bonding can be either ______________ or __________________, dependent on the strength of
the attraction of each atom for the shared electrons.
1. A _________________ __________________ bond is a covalent bond in which the bonding electrons are
shared _________________ by the bonded atoms.
a. Generally speaking, ________________ _________________ bonds occur between atoms with
electronegativity differences of _________________.
2. A ____________________ bond is a covalent bond in which the bonded atoms have an
___________________ attraction for the shared electrons.
a. Generally speaking, ______________________ bonds occur between atoms with electronegativity
differences of _________________.
b. A _______________ is used to represent this ______________ sharing of electrons. A
______________ is represented by an ______________ with the head pointing toward the
_________________ pole and a crossed tail pointing toward the ___________________ pole.
Periodic Table
of
Electronegativity
The Periodic Table
Unit 5 Page 7
Learning Target:
I will be able to describe the nature of metallic bonding and apply the theory to explain metallic properties such as
thermal and electrical conductivity, malleability, and ductility.
Criteria for Success:
I can explain why the sea of electrons in metals gives metals their unique properties.
Introduction to metallic bonds
A. The chemical bonding that results from the attraction between metals atoms and the surrounding sea of
_________________ is called ___________________ bonding.
1. Most metals have very few _________________ in their outermost energy shells, and some have vacant
outer electron orbitals. That means its valence electrons are _________________ and free to move around.
2. When metals are next to each other, the valence electrons don't just stay on their own atom; they roam
around the _______________ ________________ _____________________.
3. Each metal atom allows its electrons to ___________ ______________, so these atoms become positively
charged cations.
a. These cations are kind of like a positively charged island and are surrounded by a sea of negatively
charged electrons. The attraction between the ___________________ electrons and
________________ center is a metal bond.
Metallic bond properties
A. In metal bonds, the electrons ____________ ________________ around in an electron sea, and this leads to metals'
unique properties.
1. Metal ____________ __________________ well because all of the mobile electrons are free to move towards
any attraction.
2. Metals have ___________ (shiny) because it reflects incoming light photons (because of the free electrons.)
3. It is _____________________ because the structure and uniform bonding in all directions of the metal allow
the atoms to ______________ past each other without breaking.
a. ________________ is the ability of a substance to be hammered or beaten into thin sheets.
b. ________________ is the ability of a substance to be drawn or pulled through a small opening to
produce a wire.
Bonding
Unit 5 Page 8
Learning Target:
I can represent the structure of a molecule by drawing bonds and unshared pairs.
Criteria for Success:
I can construct electron dot structures to illustrate covalent bonds.
A.________________are formulas used to model what atoms look like in a compound that contains atoms that are
________________bonded together. Remember that in a ________________ bond, __________________
atoms ________________electrons in order to obtain a full valence shell. For _______________________ , a full
valence shell will have ________________ electrons. For all other nonmetals, a full valence shell will have
__________________. The idea that nonmetals will ____________________ electrons to get
_______________________ valence electrons and be ______________________ is part of the
______________________.
1. Element symbols represent the atom’s ________________.
2. ________________electrons are then represented using either dot-pairs or dashes.
a. If the valence electrons are not involved in bonding they are represented using
_______________________. These represent unshared pairs of electrons.
b. If the valence electrons are involved in bonding they are represented using a _________________
between two atomic symbols. These represent shared electron pairs in covalent bonds.
i. Remember that _______________________are formed when
_____________________ ________________valence electrons in order to mutually achieve
_____________________valence shells (to be ________________ like noble gases).
ii. Only valence electrons that are already _______________________ will be shared from
one atom to another.
Use the space below to draw examples of atoms sharing unpaired electrons.
Ex. 1
Ex. 2
Ex. 3
Ex. 4
Notice that a pattern shows up for covalent bonds with certain atoms. Certain atoms are most
_______________________with a specific number of _________________and a specific number of
__________________ (_____________________) _______________________of electrons.
Element
# bonds
# lone pairs
H
1
0
C
4
0
N
3
1
O
2
2
All Halogens
1
3
All Noble Gases
0
4
Atoms in the same groups as C, N, and O will tend to follow the same pattern, but they may not always.
B. Steps to writing a Lewis structure of a ________________covalent compound
1. Choose a central atom.
a. If _____________________is in the molecule, it will be the _____________________ atom.
b. Otherwise, the atom that is capable of having the ________________will most likely be the
________________atom.
c. It is possible for all atoms in a molecule to be bonded in a straight line, like Example 4 above. In this
case, there is not one sole central atom. The formula for the molecule will generally be written by listing
the elements in the order they are chained in the atom. Ex: HSCN, CH3COOH
2. Write the symbol for the central atom. Then write the symbols for the other atoms around the central atom.
3. Draw the ________________for the individual atoms.
4. Figure out how to “connect the dots.”
5. Draw __________________ between atoms to show ________________ pairs of electrons. Be sure to
show the __________________ ____________________ around atoms that have them.
6. Double check that each atom has a ________________ __________________ by counting both
_________________ and ______________ ______________ as ______________ electrons each
belonging to the atom.
C. Multiple bonds, expanded octets, and other exceptions
1. Only certain atoms can form _______________________ and ________________ bonds. Generally,
they are the “________________,” although others can exist.
2. Some atoms in the ________________ and _________________ energy levels can hold electrons in
their otherwise empty ________________. This allows them to form more than 4 bonds and have more than
a full _________________. This is most common with ______________________ , although any
nonmetal that has access to ________________(so, nonmetals in the ______________________
_______________________ and ________________ ) are capable of doing it. These can have
_____________________ valence electrons in a molecule. If you are ever drawing a molecule that has lone
pairs and unsure of where else to put them, the lone pairs should go on the expanded octet atom.
3. Boron is stable with only ______________ electrons, rather than a full __________________ of
_______________. This means it can be stable with _____________________ bonds and
________________ lone pairs.
4. Some _______________ ____________________ , under extreme laboratory conditions, can be forced
to ___________________ ______________________. This has only been shown to occur with the
_______________________ ________________ noble gases (_______________ and
______________) and the most _____________________ atom (________________).
________________ is able to so strongly attract electrons to itself that it can attract valence electrons in
noble gases that have a lot of _________________.
5. Lewis structures for _____________________ __________can be drawn using generally the same
process as covalent molecules. However, the final structure must have _____________
_________________drawn around it and the ___________________must be written outside the
_____________________as a superscript in the upper right corner.
D. How to tell if you’re dealing with an exception—NAS charts
1. An NAS chart can be made for any covalent molecule. It has a built-in way to tell if you need to draw a
_______________ or _________________bond or if you are dealing with an ____________________.
2. An NAS chart keeps track of the ____________________number of electrons that are
______________________ for each to be stable with a full “octet” (2 for H, 6 for B, 8 for everything else).
3. An NAS chart also keeps track of the ___________________number of _________________electrons
_____________________. If you’re trying to draw a ________________ _________, the
________________must be added to this line. (Remember a _____________________charge means
_____________________ , so you ________that number to the A line. A _______________________
charge means electrons were ________________so __________________ that number from the A line.)
4. Finally, an NAS chart calculates how many ________________electrons will have to be in the molecule—
this number divided by ___________________ tells you how many _________________ to draw.
VSEPR
Unit 5 Page 11
Learning Target:
I can predict molecular structure for molecules with linear, trigonal planar, or tetrahedral electron pair geometries using
Valence Shell Electron Pair Repulsion theory
Criteria for Success:
I can explain VSEPR theory
I can predict the electron geometry or molecular geometry of a molecule using VSEPR theory for linear, trigonal planar,
or tetrahedral electron pair geometries.
Notes
VSEPR Theory
A. V________ S_______ E_________ P_______ R________ (VSEPR) theory is a model used to predict the
____________of individual molecules from the number of electron pairs surrounding their central atoms.
1. The premise of VSEPR is that the _________________ surrounding an atom tend to repel each other, and
will therefore adopt an arrangement that_______________ this repulsion. This will determine the ________
of the molecule.
2. The________ __________ and _______ _______ will arrange themselves as far as possible from each
other.
3. _______ _________ repel themselves more than bonding pairs.
4. __________ and _________ bonds are treated as one pair or region.
B. The "______ ___________" of electron counting is commonly used when applying the VSEPR theory.
1. The A represents the _________ ________ and always has an implied subscript one.
2. The X represents the number of ____________ that are bonded to the central atom.
3. The E represents the number of _______ _______ electrons surrounding the central atom.
4. Based on the steric number and distribution of X's(_______) and E's(_________ __________), VSEPR theory
predicts the _________ of the molecules.
Geometry of Molecules
A. 1. _________ ___________ is the geometry of the molecules describes the arrangement of _______ the atoms
and lone pair electrons around the central atom.
2. _____________ ___________ describes only the___________ around the central atom.
Molecule
Type
AX2E0
AX2E1
Shape[10]
Linear
Bent
AX2E2
Electron arrangement†[10] Geometry‡[10]
Examples
BeCl2, HgCl2, CO2
SO2 O3, CCl2
H2O, OF2
AX3E0
Trigonal planar
BF3, SO3
AX3E1
Trigonal
pyramidal
NH3, PCl3
AX4E0
Tetrahedral
CH4, TiCl4, XeO4
AX4E2
Square planar
XeF4
AX5E0
Trigonal
bipyramidal
PCl5
AX6E0
Octahedral
SF6, WCl6
Bonding
Unit 5 Page 13
Learning Target:
I can describe intermolecular forces.
Criteria for Success:
I can use my understanding of intermolecular forces and molecular geometry to explain how to predict molecular
polarity.
Molecular Polarity and Intermolecular Forces
Molecular Polarity
A. ____________ molecules act as tiny ____________ because of their uneven charge distribution. A ____________ is
created by equal but opposite charges that are separated by a short distance.
1. Molecular polarity depends on both the _______________ and _______________________ of each bond.
Intermolecular Forces—Forces of Attraction Between Molecules
A. There are two types of __________ intermolecular forces collectively known as ________________ forces.
1. The forces of attraction between ____________ molecules are known as ___________________ forces. This
interaction is similar to ionic bonds but much, much _______________.
2. __________________ forces are the weakest of the intermolecular forces and result from the constant motion
of electrons and the creation of instantaneous dipoles.
a. Occur between ALL atoms and molecules but are the ONLY intermolecular force acting among
_____________________ atoms.
b. Strength __________________ with ___________________ numbers of electrons in the interacting
atoms or molecules.
B. The strongest intermolecular force is a specific type of strong dipole-dipole force called ________________ bonding, in
which a __________________ atom that is bonded to a _____, _____, or _____ atom is attracted to an unshared pair of
electrons of a highly electronegative atom in a nearby molecule.
1. _______________ bonding is often depicted with a ____________ line.
2. _______________ bonding is responsible for some of the unique properties of ____________, including its
relatively _________ boiling point.
Properties of Intermolecular Forces
A. _______________ point is generally a good measure of the force of attraction between molecules. It is at this point
that molecules pull away from one another in the liquid phase and enter the _______ phase.
1. The ____________ the boiling point, the _________________ the intermolecular forces between the
molecules.
B. When a liquid is in a confined, closed, container, an equilibrium exists between the liquid and its gaseous phase. This
equilibrium exists regardless of the temperature inside the container and the temperature of the liquid.
This __________________ pressure is a measure of the relative strength of the intermolecular forces, and tells you the
rate of evaporation.
1. The _____________ the vapor pressure, the ______________ the IMF (more molecules escaping the
attractions of other molecules to enter the vapor (gas) phase.