This document discusses covalent bonds and Lewis structures. It begins by listing learning objectives related to covalent bonding concepts. It then defines key terms like Lewis structure, covalent bond, and electronegativity. The document goes on to explain the formation of covalent bonds via electron sharing. It discusses exceptions to the octet rule. Guidelines are provided for drawing Lewis structures, including dealing with resonance. Various examples of Lewis structures are worked through. The document concludes with a review of naming covalent compounds.
This power point work describe about polar and nonn polar compounds and how to find it very easily and it also explain dipole moment and its calculation...this includes some workout problems
This power point work describe about polar and nonn polar compounds and how to find it very easily and it also explain dipole moment and its calculation...this includes some workout problems
Polar and nonpolar bonds and polar molecules970245
polar and nonpolar bonds are explained with example and practice work is also given diplole action is explained. polar and non-polar molecules explained.
This ppt was made for our stupid projects..... The main purpose behind uploading this ppt is that no one should suffer like us and waste their time behind these stupid things... concentrate on your studies..
Organic compounds are almost 60% of all compounds. because of carbons tendency to form a compound as it has more than1 electron(4electrons) to form covallent compounds. SO a wide range of everything we eat is formed from carbon and hydrogen, which is the second important element to form organic compounds.
Lesson 5: Corpuscles to Chemical Atomic Theory (The Development of Atomic The...Simple ABbieC
At the end of the lesson, you will have to:
1. cite the contribution of John Dalton toward the understanding of the concept of the chemical elements
2. explain how Dalton’s theory contributed to the discovery of other elements.
CH 4 CHEMICAL BONDING AND MOLECULAR STRUCTURE.pdfLUXMIKANTGIRI
English chapter we will discuss about bonding how the molecules and the ions are in texting as a molecule make the structure there energy their transmission and other
chemical bonding and molecular structure class 11sarunkumar31
hybridisation, bonding and antiboding, dipole moment, VSPER theory, Molecular orbital diagram, Phosphorous pentachloride, ionic bond, bond order, bond enthalpy, bond dissociation, sp and sp2hybridisation, hydrogen bonding,electron pair,lone pair repulsion, resonance structure of ozone, how to find electron pair and lone pair, sp3 hybridization of methane.
Polar and nonpolar bonds and polar molecules970245
polar and nonpolar bonds are explained with example and practice work is also given diplole action is explained. polar and non-polar molecules explained.
This ppt was made for our stupid projects..... The main purpose behind uploading this ppt is that no one should suffer like us and waste their time behind these stupid things... concentrate on your studies..
Organic compounds are almost 60% of all compounds. because of carbons tendency to form a compound as it has more than1 electron(4electrons) to form covallent compounds. SO a wide range of everything we eat is formed from carbon and hydrogen, which is the second important element to form organic compounds.
Lesson 5: Corpuscles to Chemical Atomic Theory (The Development of Atomic The...Simple ABbieC
At the end of the lesson, you will have to:
1. cite the contribution of John Dalton toward the understanding of the concept of the chemical elements
2. explain how Dalton’s theory contributed to the discovery of other elements.
CH 4 CHEMICAL BONDING AND MOLECULAR STRUCTURE.pdfLUXMIKANTGIRI
English chapter we will discuss about bonding how the molecules and the ions are in texting as a molecule make the structure there energy their transmission and other
chemical bonding and molecular structure class 11sarunkumar31
hybridisation, bonding and antiboding, dipole moment, VSPER theory, Molecular orbital diagram, Phosphorous pentachloride, ionic bond, bond order, bond enthalpy, bond dissociation, sp and sp2hybridisation, hydrogen bonding,electron pair,lone pair repulsion, resonance structure of ozone, how to find electron pair and lone pair, sp3 hybridization of methane.
Chemical bonding xi , dr.mona srivastava , founder masterchemclassesDR MONA Srivastava
Viewers,
This ppt of chemical bonding is designed to give a complete idea and though conceptual extract of the topic for the students of XI to help them understand the basics of chemical bonding in chemistry. Hope it covers all important aspects and points .
Dr Mona Srivastava
Founder-
Masterchemclasses
At the end of this chapter you should be able to sketch the periodic table showing the groups and periods; identify the metals, metalloids and non-metals in the periodic table. Identify the representative elements, the transition elements, the transition metals, the lanthanides and actinides in the periodic table. Also, give the electron configuration of cations and anions; determine the trends in the physical properties of elements in a group; describe and explain the trends in atomic properties in the periodic table; compare the properties of families and elements; predict the properties of individual elements based on their position in the periodic table; and perform exercises and collaborative work with peers.
What is tetrahedron,a trigonal bipyramid, and an octahedron? In this lesson you will be able to: apply the valence shell electron pair repulsion theory to predict the molecular geometry of simple molecules; define dipole moment; predict the polarity of molecules.
This would enable students to explain the emission spectrum of hydrogen using the Bohr model of the hydrogen atom; calculate the energy, wavelength, and frequencies involved in the electron transitions in the hydrogen atom; relate the emission spectra to common occurrences like fireworks and neon lights; and describe the Bohr model of the atom and the inadequacies of the Bohr model.
In this presentation you will be able to, describe how atomic orbitals arise from the Schrodinger's equation, relate orbital shapes to electron density distribution and interpret the information obtained from a four set of quantum numbers.
According to Gilbert Lewis, atoms combine i order to achieve a more stable electron configuration. Maximum stability is obtained when an atom is isoelectronic with a noble gas. This presentation would enable students to relate lattice energy with physical properties such as melting point.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
2. Learning Objectives
1. Illustrate the formation of covalent bonds in
terms of electron sharing
2. Apply the octet rule in forming covalent
compounds
3. Define electronegativity
4. Describe the electronegativity trends in the
periodic table
2
3. Learning Objectives
5. Draw Lewis structure of covalent
compounds
6. Identify lone pairs and bond pairs;
7. Draw the resonance structures of covalent
compounds
8. Determine the polarity of a bond based on
the electronegativities of the bonding
atoms
3
4. Learning Objectives
9. Determine whether a bond is ionic, polar
covalent, or covalent based on the
differences in electronegativities of the
bonding atoms
4
8. FORMATION OF THE
COVALENT BOND
▰ Gilbert Lewis suggested that the chemical
bond is formed by sharing of electrons in
atoms.
▰ Example:
▰ The two electrons are shared equally
between the two atoms forming a covalent
bond.
8
9. FORMATION OF THE
COVALENT BOND
▰ The electrons are attracted to the nuclei of
both atoms keeping the atoms together to
form a molecule.
▰ formation of the covalent bond for the F2
molecule
9
10. FORMATION OF THE
COVALENT BOND
▰ The representation of the covalent
compound is called the Lewis structure. In
the Lewis structure, shared electrons that
form a bond is represented by a line or a
pair of dots; lone pairs are represented by
dots above the atom.
10
11. FORMATION OF THE
COVALENT BOND
a. From the Lewis structure of F2, how many
electrons are around each fluorine atom in
F2?
b. How many bond pairs are there in the F2
molecule?
11
12. FORMATION OF THE
COVALENT BOND
c. How many lone pairs are there in the F2
molecule?
d. Illustrate the formation of the covalent
bond in Cl2. How many bond pairs are
there?
e. How many lone pairs?
12
14. Exercises:
1. Draw the Lewis structure for H2O, CH4
(methane), and for NH3.
2. Which of the three molecules has the
largest number of bond pairs (covalent
bonds)?
3. Draw the Lewis structure for carbon
dioxide, CO2.
14
15. ▰ The examples of CO2 and N2 show that
there are different types of covalent bonds
that are formed.
▰ Single bonds are formed when two atoms
are held together by one pair of electrons.
▰ Multiple bonds can be formed also
15
16. ▰ A double bond is from the sharing of two
pairs of electrons such as in the case of O
and C in CO2.
▰ A triple bond exists in N2 where the two N
atoms are held by three pairs of electrons.
16
17. Types of Covalent Bond
▰ Experimental evidence has shown that
electrons are not equally shared between H
and F; the electrons spend more time near F
rather than H. Therefore the electron density
is shifted more towards F rather than H.
17
18. ▰ This leaves the F end of the molecule
partially negative, δ - , and the H end of
the molecule partially positive, δ+, such
bond is referred to as a polar covalent
bond.
18
19. ▰ The polar covalent bond is somewhere
between a purely covalent (nonpolar) bond
and an ionic bond (where there is almost
complete transfer of electrons).
19
20. Electronegativity
▰ property that distinguishes the polarity of
bonds
▰ the tendency of an atom in a chemical bond
to attract electrons toward itself
▰ is a theoretical concept and devised as a
relative scale. That is, it can be estimated
relative to, or in comparison to, other
elements in chemical bonds.
20
21. Electronegativity
▰ Linus Pauling developed a relative scale of
electronegativities which is widely used in
General Chemistry
▰ In contrast, ionization energies and electron
affinities are physically measurable
properties of elements.
21
23. ▰ The difference in the electronegativity values
( EN) of two bonded atoms determines the
percent ionic character of the bond. If the
bond is between two identical elements, like
F—F, then the bond is purely covalent with
0 percent ionic character. The difference in
electronegativity is 0.
23
24. ▰ For the molecule H—Cl, the difference in
electronegativity is 0.9 showing that the bond
is a polar covalent bond. A 50% ionic
character corresponds to EN=1.7. While
there is no bond that is 100% ionic, an
electronegativity difference of 2.0 or greater
is usually classified to be predominantly ionic.
24
25. ▰ When EN ≥ 2.0, the bond is
predominantly ionic.
25
26. Exercises:
I. Classify the following bonds as ionic, polar
covalent, or covalent.
1. The C-C bond in H3CCH3
2. The K-I bond in KI
3. The C-F bond in CF4
4. The N-H bond in NH3
26
27. Exercises:
II. Arrange the following bonds according to
increasing bond polarity: Cs to F, Cl to Cl, Br
to Cl, Si to C.
27
28. Guidelines in Writing the Lewis
Structure of Covalent Molecules
1. Draw a skeletal structure of the molecule
putting bonded atoms next to each other.
In general, the least electronegative atom
occupies the central position. H and F
usually occupy terminal (end) positions.
28
29. Guidelines in Writing the Lewis
Structure of Covalent Molecules
2. Count the total number of valence
electrons from all the atoms in the
structure. Add electrons corresponding to
the charge for negative ions; subtract
electrons corresponding to the charge for
positive ions.
29
30. Guidelines in Writing the Lewis
Structure of Covalent Molecules
3. Distribute the valence electrons to the non-
central atoms such that these atoms fulfill
the octet rule. Remaining electrons are
assigned to the central atom. Remember
that bonds are equivalent to 2 electrons.
4. If the valence electrons are not enough,
multiple bonds may be formed.
30
31. Exercises
1. Write the Lewis structure for NCl3.
2. Write the Lewis structure of OCS. C is the
central atom.
3. Write the Lewis structure of CN–.
31
32. Exercises
4. Write the Lewis structure of the following
molecules:
a. Ethylene, C2H4
b. Acetylene, C2H2
c. Carbon tetrachloride, CCl4
d. COBr2 (for the skeletal structure, C is
bonded to O and Br atoms)
32
33. Lewis Structure & Resonance
▰ Write the Lewis structure for the ozone
molecule, O3.
▰ To resolve this discrepancy, we represent
the ozone molecule using the two structures
presented as:
33
34. Lewis Structure & Resonance
▰ The above structures is called a resonance
structure. The double sided arrow shows
that the structures are resonance
structures. A resonance structure is one of
two or more Lewis structures for a molecule
that cannot be represented accurately by
only one Lewis structure.
34
36. EXCEPTIONS TO THE OCTET
RULE:
The octet rule works best for second-period
elements. Hence there are many exceptions.
They fall into three categories:
a. Incomplete octet
b. Odd number of electrons
c. Expanded Octet
36
37. EXCEPTIONS TO THE OCTET
RULE:
▰ Incomplete octet
An example of a molecule with incomplete
octet is BeH2, beryllium hydride.
H – Be – H
▰ There are only 4 electrons around Be and
not 8. Boron and aluminum also form
molecules with incomplete octets.
37
38. EXCEPTIONS TO THE OCTET
RULE:
▰ Draw the Lewis structure of aluminum
triiodide, AlI3, showing the incomplete octet.
38
39. EXCEPTIONS TO THE OCTET
RULE:
▰ Molecules with Odd Number of
Electrons
▰ Examples are nitric oxide, NO, and
dinitrogen dioxide, N2O.
39
40. EXCEPTIONS TO THE OCTET
RULE:
▰ The odd numbered molecules are
sometimes referred to as radicals. They
are generally highly reactive.
40
41. EXCEPTIONS TO THE OCTET
RULE:
▰ Expanded Octets
Atoms belonging to the second period
cannot have more than eight valence
electrons around the central atom because
they only have the 2s and 2p subshells. This
is different for atoms of elements in the 3rd
period and beyond.
41
42. EXCEPTIONS TO THE OCTET
RULE:
▰ These elements have 3d orbitals that can
participate in the bonding. Hence they can
have more than eight valence electrons
around the central atom. An example is
SF6, sulfur hexafluoride and phosphorus
pentafluoride, PF5.
42
45. NAMING COVALENT
COMPOUNDS: (A REVIEW)
1. For binary compounds, state the name of
the first element. The name of the second
element ends in –ide.
HF Hydrogen fluoride
HI Hydrogen iodide
SiC Silicon carbide
45
46. NAMING COVALENT
COMPOUNDS: (A REVIEW)
2. Prefixes are used to denote the number of
atoms in the formula. The prefix “mono”
usually omitted for the first element in the
formula.
CO carbon monoxide
CO2 carbon dioxide
NO2 nitrogen dioxide
46
48. Seatwork
▰ Look for at least 2 examples of covalent
compounds that can be found in nature or
used in everyday life. Include the following
information:
a. uses of the covalent compound
b. chemical formula and chemical name of
the covalent compound
c. structure of the compound
48
50. CREDITS
Special thanks to all the people who made
and released these awesome resources for
free:
▰ Presentation template by SlidesCarnival
▰ Photographs by Startup Stock Photos
50
Editor's Notes
Only valence electrons are included in Lewis structures.
Only valence electrons are included in Lewis structures.
Only valence electrons are included in Lewis structures.
Only valence electrons are included in Lewis structures.
