Chemical bonding

CHEMICAL BONDING
CHEMICAL BONDING
Subject Physics and Chemistry
Course/Level 3º ESO/4º ESO
Primary Learning Objective Students should know atoms combine to form molecules by sharing electrons to form covalent or metallic bonds or by exchanging electrons to
form ionic bonds. They will learn to write systematic names and formulas for binary /ternary compounds.
Subject Content 1. Introduction to chemical bonds.
2. Types of chemical bonds.
2.1. Intermolecular.
2.2. Intramolecular.
2.2.1. Ionic.
2.2.2. Covalent.
2.2.3. Metallic.
3. Nomenclature of Inorganic Chemistry (IUPAC recommendation 2005)
Language Content /
Communication
Vocabulary Atom, molecule, ion, compound, electrons, neutrons, protons, electron shell/level, valence electrons, chemical bonding,
ionic bond, covalent bond, electron transfer, metals, non-metals, noble gases, Octet rule, ionic bonds, ionic charge, ionic
compound, covalent bonds, covalent compounds, single bond, double bonds, triple bonds, octet, octet rule, valence,
valence electrons, polar, nonpolar covalent, polar covalent bond…
Structures Routines: What is meant by the term “chemical bond”? Why do atoms bond with each other to form compounds? How do
atoms bond with each other to form compounds? What are ions? How do ions differ from atoms? What types of elements
form cations, and what types of elements form anions? How is a covalent bond formed? What is the major difference
between a covalent bond and an ionic bond? What are valence electrons? What is the octet rule?
Contents: Conditionals, present, future, comparatives.
Classroom management: Take out your notebook/recorder/pen, write down the following sentence, right! / you're right,
well done! / very well! / good job , etc.
Discourse type Exposition, description, argument.
Language skills Writing, reading, speaking and listening
Activities The presentation includes different activities with an explanation in order to the students answer a question or solve a problem, make
observations and collect data, and draw a conclusion as to the answer to the question or problem.
LESSON PLAN
Pp Jaramillo Romero
Dpto. Física y Química
IES Rodríguez Moñino

CHEMICAL BONDING
METHODOLOGY
Organization and class distribution / timing The number of sessions considered to develop the contents on this unit are at least 10 sessions of 50 minutes each one (+ 2 week final Project)
It’s very important to point out that the methodology will be active and participatory in order to facilitate both individual and group learning. For that, teacher
observation is very important during student's work.
Key Competences Language proficiency Know, acquire and apply the vocabulary of the subject.
Exercising a comprehensive reading of texts related to the topic.
Digital competence and treatment of
information
I use PDI to explain content and implementation of web quest by students.
Make the online activities.
Social and civic competences Fostering respect between and other values like cooperation, coeducation when they work in groups.
Autonomy and personal initiative To be autonomous for individual activities.
Evaluation Acquired content knowledge (*) Explain how the periodic table can be used to predict the likely charges for ions of a given element.
Describe the octet rule and how it is used to explain chemical behaviour.
Define and describe the arrangement of the valence electrons for a given chemical species.
Describe the general properties that distinguish ionic compounds from other substances.
Define and give examples of ionic compounds. Be able to predict which elements are likely to form ionic
compounds with each other.
Describe the crystal lattice structures adopted by ionic compounds.
Describe the general properties of metals compared to other element types.
Describe the arrangement of atoms in metallic substances.
Describe the behaviour of electrons in metals.
Define and give examples of covalent bonds.
Describe the differences between ionic and covalent bonds.
Describe Lewis structures and use Lewis structures to illustrate covalent bonds in molecules.
To write systematic names and formulas for binary and ternary compounds.
Instruments The unit will be evaluated daily with:
Individual participation in classroom activities and homework.
Works in groups.
Notebook.
Behavior.
Tests.
Glossary.
Conceptual maps
Final Project.
(*) Depends on the student’s level.
Pp Jaramillo Romero

CHEMICAL BONDING
1. Introduction to chemical bonds.
2. Types of chemical bonds.
2.1. Intermolecular.
2.2. Intramolecular.
2.2.1. Ionic.
2.2.2. Covalent.
2.2.3. Metallic.
3. Nomenclature of Inorganic Chemistry (IUPAC recommendation 2005)
OUTLINE
Pp Jaramillo Romero

CHEMICAL BONDING
 What is meant by the term “chemical bond”?
 Why do atoms bond with each other to form
compounds?
 How do atoms bond with each other to form
compounds?
 What are ions?
 What types of elements form cations, and
what types of elements form anions?
 What are valence electrons?
 What is the octet rule?
CHEMICAL BONDING
Pp Jaramillo Romero

CHEMICAL BONDING
1. INTRODUCTION TO CHEMICAL BONDS
008
THE OCTECT RULE
Atoms or ions are held together in molecules or compounds by chemical
bonds. This will help us understand how to:
- Predict the shapes of molecules.
- Predict properties of substances.
- Design and build molecules with particular sets of chemical and physical
properties.
Chemical compounds tend to
form so that each atom, by
gaining, losing, or sharing
electrons, has eight electrons
in its highest occupied energy
level. The same number of
electrons as in the nearest
noble gas.
Pp Jaramillo Romero

CHEMICAL BONDING
Bonding Forces
 Electron – electron
repulsive forces
 Nucleus – nucleus
repulsive forces
 Electron – nucleus
attractive forces
Activity 1.1: Intermolecular and intramolecular bonds
Pp Jaramillo Romero

CHEMICAL BONDING
Activity 1.2: Video about chemical bonding: AQA GCSE
Chemistry Unit C2.1 Structure and bonding (part 1)
Activity 1.3: Video about chemical ionic bond: AQA GCSE
Chemistry Unit C2.1 - Structure and bonding (part 2)
Activity 1.4: Video about chemical bonding: GCSE
BBC Science Bitesize - Bonding
Pp Jaramillo Romero

CHEMICAL BONDING
2. TYPES OF CHEMICAL BONDS
 There are two major categories of bonds
Intermolecular
&
Intramolecular
(between)
(within)
Pp Jaramillo Romero

CHEMICAL BONDING
2.1. INTERMOLECULAR
There are three different types of intermolecular bonds
Bond type Bond strength
Hydrogen Strong
Dipole-Dipole Medium
London Forces Weak
(Dispersion)
Activity 2.1: Intermolecular forces
Pp Jaramillo Romero

CHEMICAL BONDING
2.1. INTERMOLECULAR
HYDROGEN BONDS
 These bonds may occur between covalent polar
molecules.
 H-bonds occur when Hydrogen of one molecule is
bonded DIRECTLY to an atom of F, O, or N atom
from an adjacent molecule.
Pp Jaramillo Romero

CHEMICAL BONDING
2.1. INTERMOLECULAR
DIPOLE – DIPOLE BONDS
May occur between polar covalent molecules.
There is an attraction between the positive end of
one molecule and the negative end of another
molecule.
Pp Jaramillo Romero

CHEMICAL BONDING
2.1. INTERMOLECULAR
LONDON FORCES
These bonds occur between nonpolar molecules.
Pp Jaramillo Romero

CHEMICAL BONDING
2.2. INTRAMOLECULAR
There are three different types of intermolecular bonds
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.1. IONIC
Ionic bonds are formed by the attraction of oppositely
charged ions.
Neutral atoms come near each
other. Electron(s) are transferred
from the metal atom to the non-
metal atom. They stick together
because of electrostatic forces,
like magnets.
Activity 2.2.1.1: Ionic bonding
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.1. IONIC
 Metal to nonmetal.
 Metal loses electrons to form cation.
 Nonmetal gains electrons to form anion.
 The electronegativity between the metal and the nonmetal must be > than 2.
 Ionic bond results from + to − attraction.
 Larger charge = stronger attraction.
 Smaller ion = stronger attraction.
 Lewis theory allows us to predict the correct formulas of ionic compounds.
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.1. IONIC
Structure of ionic crystals
Different types of crystals are formed
depending on the ionic radii and the charge
of the ions involved.
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.1. IONIC
Properties of ionic compounds
• Crystalline structure. A regular repeating arrangement of ions in the
solid.
• Ions are strongly bonded.
• Ionic compounds are very hard.
• High melting and boiling points.
• Conducting electricity is allowing charges to move.
– In a solid, the ions are locked in place. Ionic solids are insulators.
– When melted, the ions can move around. Melted ionic compounds conduct.
– Dissolved in water they conduct.
• Many soluble in water but not in nonpolar liquid.
• Ionic solids are brittle.
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.1. IONIC
Strong repulsion breaks crystal apart
Ionic solids are brittle.
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.2. COVALENT
Covalent bonds are formed when an
atom of one non-metal shares one or
more electrons with an atom of another
non metal so both atoms end up with
eight valence electrons.
Activity 2.2.2.1: Covalent bonding
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.2. COVALENT
 Often found between two non-metals or Hydrogen.
 Typical of molecular species.
 Atoms bonded together to form molecules.
 Strong attraction.
 Atoms share pairs of electrons to attain octets.
 Molecules generally weakly attracted to each other.
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.2. COVALENT
Covalent bond strength depends on the number of
electron pairs shared by the atoms.
single
bond
double
bond
triple
bond
< <
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.2. COVALENT
Single Covalent Bonds
 Two atoms share one pair of electrons.
 2 electrons.
 One atom may have more than one single bond.
F
••
••
••
• F
••
••
•
••
H•H• O
••
•
•
••
F F
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.2. COVALENT
Double Covalent Bond
 Two atoms sharing two pairs of electrons.
 4 electrons.
 Shorter and stronger than single bond.
O
••
•
•
••
O
••
•
•••
O O
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.2. COVALENT
Triple Covalent Bond
 Two atoms sharing three pairs of electrons.
 6 electrons.
 Shorter and stronger than double bond.
N
••
•
• N
••
• •
NN
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.2. COVALENT
NONPOLAR COVALENT BOND
• When the atoms in a bond are the
same, the electrons are shared
equally.
POLAR COVALENT BOND
• When two different atoms are
connected, the atoms may not be
shared equally.
Polar vs Nonpolar
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.2. COVALENT
Polar vs Nonpolar
 Bonding between unlike atoms results in unequal sharing of the
electrons.
 One atom pulls the electrons in the bond closer to its side.
 One end of the bond has larger electron density than the other.
 The result is bond polarity.
 The end with the larger electron density gets a partial negative
charge and the end that is electron deficient gets a partial
positive charge.
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.2. COVALENT
• How do we measure how strong the atoms pull on electrons?
Polar vs Nonpolar
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.2. COVALENT
Polar vs Nonpolar
Electronegativity difference (∆) Bond
∆ > 2 Ionic
0.4 < ∆ < 2 Polar covalent
∆ < 0.4 Covalent
In practice no bond is totally ionic. There will always be a small
amount of electron sharing.
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.2. COVALENT
Percent ionic character of chemical bonds as a
function of electronegativity difference
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.2. COVALENT
Rules for Lewis structures of
molecules
1. Write out valence electrons for each atom.
2. Connect lone electrons because lone electrons are destabilizing.
1. Become two shared electrons.
1. Called a “bond.”
3. Check to see if octet rule is satisfied.
1. Recall electron configuration resembling noble gas.
1. In other words, there must be 8 electrons (bonded or
non-bonded) around atom.
1. Non-bonded electron-pair.
1. Called “lone pair”.
Pp Jaramillo Romero

CHEMICAL BONDING
Properties of covalent compounds
Some Common Features of Materials with Covalent Bonds:
• Soft-tend to be gases, liquids or soft solids.
• Poor conductors of heat and electricity.
• Molecules. Forces between molecules are weak.
• Brittle or cleave rather than deform.
• Nonelectrolytes-do not conduct electricity in water.
• Low melting and boiling points.
• Many soluble in nonpolar liquid but not in water.
However, the atoms could be bonded covalently
in a continuous network.
Pp Jaramillo Romero

CHEMICAL BONDING
Network solids
A network solid is a chemical compound where the atoms are
bonded covalently in a continuous network. In a network solid there
are no individual molecules and the entire crystal is the molecule.
Examples of network solids include diamond with a continuous
network of carbon atoms and silicon dioxide or quartz with a
continuous three dimensional network of SiO2 units. Graphite a
consist of continuous two dimensional layers covalently bonded
within the layer with other bond types holding the layers together.
Activity 2.2.2.2: Video about network solids
Pp Jaramillo Romero

CHEMICAL BONDING
Properties of covalent network solids
• Graphite- A 2-dimensional network
solid is arranged in layers, with
weak attractions between the
layers. This makes them generally
soft and/or slippery. Conductor.
Insoluble.
• Diamond/quartz-A 3-dimensional
network is a giant interlocking
design, giving the substance
exceptional hardness and a high
melting and boiling point. Good
insulators. Insoluble.
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.2. COVALENT
Lewis structures
Write the Lewis Structure for the following molecules:
1) H2O
2) CCl4
1) Where does the carbon go & why?
3) PH3
4) H2Se
5) C2H6
Activity 2.2.2.3: Lewis structures.
Pp Jaramillo Romero

CHEMICAL BONDING
Challenge
What do you know about allotropes of carbon
and nanochemistry?
Students have to design a presentation about
this topic.
2.2.2. COVALENT
Activity 2.2.2.4: Song about ionic and covalent bonds
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.3. METALLIC
Metallic solids are held
together by metallic bonds.
Metal atoms release some of
their electrons to be shared by
all the other atoms in the
crystal.
The metallic bond is the
attraction of the metal cations
for the mobile electrons.
Often described as islands of cations in a sea of electrons.
Activity 2.2.3.1: Metallic bonding
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CHEMICAL BONDING
2.2.3. METALLIC
• More than 80 elements in the periodic table are metals.
• Metals are solids at ordinary temperature and pressure, with the
exception (of mercury and gallium).
• High thermal and electrical conductivity.
• Luster and high reflectivity.
• Malleability and ductility. They can be beaten or shaped without
fracture.
• Variability of mechanical strengths (ranging from soft alkali metals to
Tungsten, which is hard).
Properties of metallic compounds
Pp Jaramillo Romero

CHEMICAL BONDING
2.2.3. METALLIC
IONIC COMPOUNDS vs METALS
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CHEMICAL BONDING
3. NOMENCLATURE OF INORGANIC CHEMISTRY
(IUPAC RECOMMENDATION 2005)
Formulación y nomenclatura química inorgánica
Nomenclature of inorganic chemistry (IUPAC
recommendation 2005)
Rules for naming Inorganic Compounds
Pp Jaramillo Romero

CHEMICAL BONDING
BIBLIOGRAPHY
VIDEOS
- https://www.youtube.com/watch?v=5PmCKWcJ7wI
- https://www.youtube.com/watch?v=GnswLP4t6d0
- https://www.youtube.com/watch?v=ShCqo34hyic
- https://www.youtube.com/watch?v=eVv3TpaQ2-A
- https://www.youtube.com/watch?v=QIfTT-_-xLo
- https://www.youtube.com/watch?v=R0g-H1dcfnY
- https://www.youtube.com/watch?v=jVfV2_dCHE8
- https://www.youtube.com/watch?v=hiyTfhjeF_U
- https://www.youtube.com/watch?v=Mo4Vfqt5v2A
- https://www.youtube.com/watch?v=-QqTwJzi7Wo
Pp Jaramillo Romero

CHEMICAL BONDING
BIBLIOGRAPHY
WEBSITES
- http://web.educastur.princast.es/proyectos/fisquiweb/
Formulacion/Inorganica/Portada.htm
- http://chsweb.lr.k12.nj.us/tpol/PowerPoint-
Chem/CHEMICAL%20BONDING.ppt
- http://hbar.phys.boun.edu.tr/~sevgena/sci101/
5.%20Chemical%20Bonding.ppt
- http://www.chem.uci.edu/~potma/COSMOS/Lecture4.ppt
- https://www.google.es/url?sa=t&rct=j&q=&esrc=s&source=
web&cd=10&cad=rja&uact=8&ved=0CHEQFjAJahUKEwj8nKH5r5fIAh
UDtRoKHfw7ASc&url=http%3A%2F%2Fwww.nuigalway.ie%2Fchem%
2FFawaz%2FSemester%25201-
Bonding%2520Lecture1.ppt&usg=AFQjCNFXh5OfcTmhUvyYj4ELmPlc
A36MMA&sig2=7BMMJEsPUhyfNEL1pZ5Opw
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CHEMICAL BONDING
BIBLIOGRAPHY
WEBSITES
web&cd=1&cad=rja&uact=8&ved=0CCgQFjAAahUKEwj8nKH5r5fI
AhUDtRoKHfw7ASc&url=http%3A%2F%2Feducation.jlab.org%2Fjs
at%2Fpowerpoint%2Fchembond.ppt&usg=AFQjCNEBfI_1oWFNM
vWL2vKeO1MKiWUcJA&sig2=QuPt1cF305rTKzi1qg4jrg
-http://www2.bakersfieldcollege.edu/dkimball/
Chemistry%20B2A/WEBPPTWithoutLectureQuizes/chapter12%20
Chemical%20Bonding.ppt
web&cd=3&cad=rja&uact=8&ved=0CDgQFjACahUKEwj8nKH5r5fI
AhUDtRoKHfw7ASc&url=http%3A%2F%2Fes.slideshare.net%2FLal
einPajarillo%2Fchemical-bonding-
powerpoint&usg=AFQjCNHkURnufyzzr0IHT3L7OsGY66Oayg&sig2
=7h4bBZhB2CCyFo39IIDx7A
Pp Jaramillo Romero

CHEMICAL BONDING
BIBLIOGRAPHY
WEBSITES
- https://www.google.es/url?sa=t&rct=j&q=&esrc=
s&source=web&cd=8&cad=rja&uact=8&ved=0CGEQFjAHahUK
Ewj8nKH5r5fIAhUDtRoKHfw7ASc&url=http%3A%2F%2Fwww.
midlandisd.net%2Fcms%2Flib01%2FTX01000898%2FCentricity
%2FDomain%2F1897%2FBonding.ppt&usg=AFQjCNG47Bsw5P
R1nzm05IrVLmn_1V0wZw&sig2=YRGqLBT3fJrj3udW22j-Hw
- https://www.google.es/url?sa=t&rct=j&q=&esrc=
s&source=web&cd=4&cad=rja&uact=8&ved=0CEEQFjADahUK
Ewj8nKH5r5fIAhUDtRoKHfw7ASc&url=http%3A%2F%2Fchem.
yu.edu.jo%2Frawash%2Fchem%2520611%2Fintro%2520to%25
20bonding.ppt&usg=AFQjCNFrGLUdzshlv51xzJwo9N7X8ujQ9
w&sig2=3N5KPvphSl9SvuPoIwhl-Q
Pp Jaramillo Romero

CHEMICAL BONDING
BIBLIOGRAPHY
WEBSITES
web&cd=2&cad=rja&uact=8&ved=0CDAQFjABahUKEwj8nKH5r5
fIAhUDtRoKHfw7ASc&url=http%3A%2F%2Fweb.clark.edu%2Faa
liabadi%2F139_chap10.ppt&usg=AFQjCNFEBR6kAyZ_hOzTiPZn8
uSu72IZTg&sig2=vkBHMn9ETg3hoW2dVHlLLw
web&cd=4&cad=rja&uact=8&ved=0CEEQFjADahUKEwj8nKH5r5f
IAhUDtRoKHfw7ASc&url=http%3A%2F%2Fchem.yu.edu.jo%2Fra
wash%2Fchem%2520611%2Fintro%2520to%2520bonding.ppt&
usg=AFQjCNFrGLUdzshlv51xzJwo9N7X8ujQ9w&sig2=3N5KPvphS
l9SvuPoIwhl-Q
Pp Jaramillo Romero

Chemical bonding

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