A chemical bond is a lasting attraction between atoms that enables the formation of chemical compounds or substance . The bond may result from the electrostatic force of attraction between atoms with opposite charges, or through the sharing of electrons as in the covalent bonds........
A detailed presentation about what is MOT. Explaining its principles, sigma and pi bonds, bond order, and molecular stability. A good and knowledgeable presentation to understand these concepts.
A chemical bond is a lasting attraction between atoms that enables the formation of chemical compounds or substance . The bond may result from the electrostatic force of attraction between atoms with opposite charges, or through the sharing of electrons as in the covalent bonds........
A detailed presentation about what is MOT. Explaining its principles, sigma and pi bonds, bond order, and molecular stability. A good and knowledgeable presentation to understand these concepts.
Valence shell electron pair repulsion theory (VSEPR THEORY)Altamash Ali
Designed in a very easy manner so that u all are able to understand each and everything easily.
Gillespie & Nyholm proposed this theory ion 1957 and its is based on the direction of bonds in a polyatomic molecule.
Based on this there are several postulate that are very necessary to know before any molecule to study.
The electrons which are involved in bond formatio.pdfrakeshankur
The electrons which are involved in bond formation between atoms are found in the
outermost shell (sometimes in the next to the outer-most shell) of the neutral atom; these are
called VALENCE ELECTRONS. The atoms of elements which have only one or two electrons
in their outermost shells (active shells) may lose electrons when they combine with atoms of
other elements. An atom which has lost one or more valence electrons possesses a positive
charge, and is called a POSITIVE ION. The sodium atom loses its one valence electron and
acquires a +1 charge when it enters into chemical combination with an atom of an element such
as chlorine. The magnesium atom may lose its two valence electrons and assume a +2 charge.
Na Na+ + e- The Na symbol to the left of the arrow represents a stable sodium atom while the
Na+ symbol to the right of the arrow represents an unstable sodium ion which has had a single
electron removed. Mg Mg++ + 2e- The Mg symbol to the left of the arrow represents a stable
magnesium atom while the Mg++ symbol to the right of the arrow represents an unstable
magnesium ion which has had two electrons removed. The smaller the number of valence
electrons in the atom, the greater the tendency of the element to lose electrons and thus form
positive ions during chemical combination with atoms of other elements. The energy required to
remove an electron from a neutral atom to form a positive ion is called the IONIZATION
POTENTIAL of the atom. Some metals have small ionization potentials and readily form
positive ions. The nonmetals, which have more electrons in their outer shells than the metals,
have large ionization potentials and show little tendency toward the formation of positive ions.
Atoms which lack one or two electrons of having an outermost shell of eight electrons readily
gain sufficient electrons from certain other atoms, such as sodium and magnesium, to make a full
compliment of eight electrons in the outside shell. Neutral atoms become NEGATIVE IONS by
gaining electrons. The nonmetals, such as Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I),
Oxygen (O), Nitrogen (N) and Sulfur (S), readily form negative ions. Cl + e- Cl- Chlorine,
when in its stable form, possesses seven valence electrons and therefore has the ability to gain
one electron (as represented to the left of the arrow) giving it a negative charge of one when in
its unstable ionic form (as represented to the right of the arrow above). S + 2e- S-2 Sulfur, when
in its stable form, possesses six valence electrons and therefore has the ability to gain two
electrons giving it a negative charge of two when in its unstable ionic form. The attraction of a
neutral atom for electrons is known as its ELECTRON AFFINITY. The nonmetals have high
electron affinities and the metals have very low electron affinities. Thus, mainly the nonmetals
tend to form negative ions during chemical combination. When a positive ion and a negative ion
are brought close together, strong electr.
Valence shell electron pair repulsion theory (VSEPR THEORY)Altamash Ali
Designed in a very easy manner so that u all are able to understand each and everything easily.
Gillespie & Nyholm proposed this theory ion 1957 and its is based on the direction of bonds in a polyatomic molecule.
Based on this there are several postulate that are very necessary to know before any molecule to study.
The electrons which are involved in bond formatio.pdfrakeshankur
The electrons which are involved in bond formation between atoms are found in the
outermost shell (sometimes in the next to the outer-most shell) of the neutral atom; these are
called VALENCE ELECTRONS. The atoms of elements which have only one or two electrons
in their outermost shells (active shells) may lose electrons when they combine with atoms of
other elements. An atom which has lost one or more valence electrons possesses a positive
charge, and is called a POSITIVE ION. The sodium atom loses its one valence electron and
acquires a +1 charge when it enters into chemical combination with an atom of an element such
as chlorine. The magnesium atom may lose its two valence electrons and assume a +2 charge.
Na Na+ + e- The Na symbol to the left of the arrow represents a stable sodium atom while the
Na+ symbol to the right of the arrow represents an unstable sodium ion which has had a single
electron removed. Mg Mg++ + 2e- The Mg symbol to the left of the arrow represents a stable
magnesium atom while the Mg++ symbol to the right of the arrow represents an unstable
magnesium ion which has had two electrons removed. The smaller the number of valence
electrons in the atom, the greater the tendency of the element to lose electrons and thus form
positive ions during chemical combination with atoms of other elements. The energy required to
remove an electron from a neutral atom to form a positive ion is called the IONIZATION
POTENTIAL of the atom. Some metals have small ionization potentials and readily form
positive ions. The nonmetals, which have more electrons in their outer shells than the metals,
have large ionization potentials and show little tendency toward the formation of positive ions.
Atoms which lack one or two electrons of having an outermost shell of eight electrons readily
gain sufficient electrons from certain other atoms, such as sodium and magnesium, to make a full
compliment of eight electrons in the outside shell. Neutral atoms become NEGATIVE IONS by
gaining electrons. The nonmetals, such as Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I),
Oxygen (O), Nitrogen (N) and Sulfur (S), readily form negative ions. Cl + e- Cl- Chlorine,
when in its stable form, possesses seven valence electrons and therefore has the ability to gain
one electron (as represented to the left of the arrow) giving it a negative charge of one when in
its unstable ionic form (as represented to the right of the arrow above). S + 2e- S-2 Sulfur, when
in its stable form, possesses six valence electrons and therefore has the ability to gain two
electrons giving it a negative charge of two when in its unstable ionic form. The attraction of a
neutral atom for electrons is known as its ELECTRON AFFINITY. The nonmetals have high
electron affinities and the metals have very low electron affinities. Thus, mainly the nonmetals
tend to form negative ions during chemical combination. When a positive ion and a negative ion
are brought close together, strong electr.
The attractive force which holds various constituents (atom, ions, etc.) together and stabilizes them by the overall loss of energy is known as chemical bonding. Therefore, it can be understood that chemical compounds are reliant on the strength of the chemical bonds between its constituents; The stronger the bonding between the constituents, the more stable the resulting compound would be.
The attractive force which holds various constituents (atom, ions, etc.) together and stabilizes them by the overall loss of energy is known as chemical bonding. Therefore, it can be understood that chemical compounds are reliant on the strength of the chemical bonds between its constituents; The stronger the bonding between the constituents, the more stable the resulting compound would be.
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.
The chemical Bond: Electronic concept of valency. Different types of chemical bond e.g. ionic, covalent, coordinate covalent metallic, dipole, hydrogen bond etc. Theories of covalent bonding and hybridization.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
2. CHEMICAL BONDING
A chemical bond is defined as
the attractive force that hold
two or more atoms together in a
molecule or an ion.
3. WHY DO ATOMS COMBINE
Atoms combine because they are not stable
unless their valence orbital is full of
electrons. In order to fill this outer orbital they
will share, give, or take electrons from other
atoms.
4. HOW DO ATOMS COMBINE
Atoms can atoms combine in the following two
ways :
1. Transfer of one or more electrons from the
valence shell of one atom to the valence shell
of another atom.
2. One , two or three electron pairs of the valence
shell of both the combining atoms are shared
between them.
5. TYPES OF CHEMICAL BONDS
Two types:
• Strong Bonds
• Weak Bonds
Strong Bonds:
I. Ionic Bond
II. Covalent Bond
III. Coordinate or Dative Covalent Bond
IV. Metallic Bond
Weak Bond
I. Hydrogen Bond
II. Vander Waals Interaction
6. IONIC BOND
An ionic bond is a type of chemical bond that involves
a metal and a non-metal ion (or polyatomic ions such
as ammonium) through electrostatic attraction. In short, it is a
bond formed by the attraction between two oppositely charged
ions.
7. How are ionic BONDS FORMED
The metal donates one or more electrons, forming a positively charged
ion or cation with a stable electron configuration. These electrons then
enter the non metal, causing it to form a negatively charged ion or
anion which also has a stable electron configuration. The electrostatic
attraction between the oppositely charged ions causes them to come
together and form a bond.
For example, common table salt is sodium chloride.
When sodium (Na) and chlorine (Cl) are combined, the sodium atoms
each lose an electron, forming cations (Na+), and the chlorine atoms
each gain an electron to form anions (Cl−). These ions are then
attracted to each other in a 1:1 ratio to form sodium chloride (NaCl).
The removal of electrons from the atoms is endothermic and causes
the ions to have a higher energy. There may also be energy changes
associated with breaking of existing bonds or the addition of more
than one electron to form anions. However, the attraction of the ions
to each other lowers their energy.
8.
9. Factors or conditions for favoring ionic compounds
I. Ionization Enthalpy (Energy) : Lesser the value of ionization enthalpy,
greater the tendency of the atom to form cation. For example, alkali
metals form cations easily because of the low value of ionization
energies.
II. Electron gain enthalpy : Greater the value of electron gain enthalpy,
more the tendency of the atom to form anion .For example ,halogens
have high electron gain enthalpies within the respective periods and form
ionic compounds easily .
III. Lattice enthalpy : It is the energy released when the close packing of
the gaseous ions of the opposite charge forms one mole of ionic solid.
Magnitude of lattice energy gives an idea about the inter-ionic forces and
it also gives the measure of the stability of the ionic compound which
depends upon the following factors.
IV. Size of the ion : Smaller the size of the ion s, lesser the inter nuclear
distance and greater the inter ionic interaction, hence, larger the
magnitude of lattice energy
V. Charge on the ions : Larger the magnitude of the charge on the ions
greater will be the attractive forces and higher the negative value of
10. covalent BOND
A chemical bond in which two atoms share some
of their valence electrons, thereby creating
a force that holds the atoms together.
Usually each atom contributes one electron to
form a pair of electrons that are shared by both
atoms.
11. A clear example is the molecule of chlorine, chlorine occurs in nature
as a molecule composed of 2 atoms of chlorine, chlorine atoms are
linked by a covalent bond produced by the sharing of 2 electrons.
During this process two atoms are join together to form one molecule,
ignoring the molecular orbital theory, bonding / anti bonding and in
order to explain it simply, we can say that 2 atomic orbital (Cl + Cl)
combine to form a new molecular orbital (Cl2).
The orbital are defined as regions of the atoms or molecules where
the electrons are localized.
12. There are three types of covalent bond depending upon the number of shared electron
pairs.
I. SINGLE COVALENT BOND
II. DOUBLE COVALENT BOND
III. TRIPLE COVALENT BOND
SINGLE COVALENT BOND
A covalent bond formed by the mutual sharing of one electron pair between
two atoms is called a “Single Covalent bond”
Examples:
13. DOUBLE COVALENT BOND
A covalent bond formed between two atoms by the mutual sharing of two
electron pairs is called a "double covalent bond".
Examples:
TRIPLE COVALENT BOND
A covalent bond formed by the mutual sharing of three electron pairs is
called a "Triple covalent bond".
Examples:
14. POLAR COVALENT BOND
A covalent bond formed between two different atoms is known as Polar covalent bond.
For example when a Covalent bond is formed between H and Cl , it is polar in nature
because Cl is more electronegative than H atom . Therefore, electron cloud is shifted
towards Cl atom. Due to this reason a partial -ve charge appeared on Cl atom and an
equal +ve charge on H atom.
Examples:
NON-POLAR BOND
A covalent bond formed between two like atoms is known as Non-polar bond.
Since difference of electro negativity is zero therefore, both atoms attract electron pair
equally and no charge appears on any atom and the whole molecule becomes neutral.
Examples:
15. Coordinate or Dative Covalent Bond
A dipolar bond, also known as coordinate
link, coordinate covalent bond, dative bond,
or semi polar bond, is a description
of covalent bonding between two atoms in which
both electrons shared in the bond come from the
same atom.
16. The reaction between ammonia and hydrogen chloride
• If these colorless gases are allowed to mix, a thick white
smoke of solid ammonium chloride is formed.
• Ammonium ions, NH4
+, are formed by the transfer of a
hydrogen ion from the hydrogen chloride to the lone pair of
electrons on the ammonia molecule.
17. When the ammonium ion, NH4
+, is formed, the fourth hydrogen is
attached by a dative covalent bond, because only the hydrogen's
nucleus is transferred from the chlorine to the nitrogen. The hydrogen's
electron is left behind on the chlorine to form a negative chloride ion.
Once the ammonium ion has been formed it is impossible to tell any
difference between the dative covalent and the ordinary covalent
bonds. Although the electrons are shown differently in the diagram,
there is no difference between them in reality.
18.
19. metallic bond
The chemical bond characteristic of metals, in
which mobile valence electrons are shared
among atoms in a usually stable crystalline
structure.
20. The structure of a metallic bond is quite different from
covalent and ionic bonds. In a metal bond, the valence
electrons are delocalized, meaning that an atom's electrons
do not stay around that one nucleus. In a metallic bond, the
positive atomic nuclei (sometimes called the 'atomic
kernels') are surrounded by a sea of delocalized electrons
which are attracted to the nuclei
Positive atomic nuclei (+) surrounded by delocalized electrons (∙)
21. PROPERTIES OF METALIC BOND
Formed between atoms of metallic
elements
Electron cloud around atoms
Good conductors at all states, lustrous,
very high melting points
Examples; Na, Fe, Al, Au, Co
22. hydrogen bond
An electrostatic attraction between a hydrogen
atom in one polar molecule (as of water) and a
small electronegative atom (as of oxygen,
nitrogen, or fluorine) in usually another molecule
of the same or a different polar substance
23. Hydrogen bonds only form between hydrogen and oxygen (O), nitrogen (N) or fluorine (F).
Hydrogen bonds are very specific and lead to certain molecules having special properties due
to these types of bonds. Hydrogen bonding sometimes results in the element that is not
hydrogen (oxygen, for example) having a lone pair of electrons on the atom, making it polar.
Lone pairs of electrons are non-bonding electrons that sit in twos (pairs) on the central atom
of the compound. Water, for example, exhibits hydrogen bonding and polarity as a result of
the bonding. This is shown in the diagram below. Because of this polarity, the oxygen end of
the molecule would repel negative atoms like itself, while attracting positive atoms, like
hydrogen. Hydrogen, which becomes slightly positive, would repel positive atoms (like other
hydrogen atoms) and attract negative atoms (such as oxygen atoms). This positive and
negative attraction system helps water molecules stick together, which is what makes the
boiling point of water high (as it takes more energy to break these bonds between water
molecules).
In addition to the four types of chemical bonds, there are also three categories bonds fit into:
single, double, and triple. Single bonds involve one pair of shared electrons between two
atoms. Double bonds involve two pairs of shared electrons between two atoms, and triple
bonds involve three pairs of shared electrons between two atoms. These bonds take on
different natures due to the differing amounts of electrons needed and able to be given up.
24. Vander Waals Interaction
Van der Waals forces include attractions between atoms,
molecules, and surfaces. They differ from covalent and
ionic bonding in that they are caused by correlations in the
fluctuating polarizations of nearby particles (a
consequence of quantum dynamics).
