1. The document discusses covalent bonding and metallic bonding. It provides examples of covalent bonding in molecules like hydrogen (H2), chlorine (Cl2), and oxygen (O2) which form when atoms share electrons.
2. Covalent substances can exist as either simple molecular structures held by weak van der Waals forces, or giant covalent structures with strong bonds like diamond and graphite.
3. Properties like low melting points, volatility, and inability to conduct electricity are explained by the weak intermolecular forces in simple covalent molecules. Giant covalent structures have properties derived from their extensive strong bonding networks.
The compounds which are made up of ions are known as ionic compounds.
In an ionic compound, the positively charged ions and negatively charged ions are held together by the strong electrostatic forces of attraction.
The forces which hold the ions together in an ionic compound are known as ionic bonds and electrovalent bonds.
The compounds which are made up of ions are known as ionic compounds.
In an ionic compound, the positively charged ions and negatively charged ions are held together by the strong electrostatic forces of attraction.
The forces which hold the ions together in an ionic compound are known as ionic bonds and electrovalent bonds.
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.
Organic reactions are chemical reactions involving organic compounds. Organic reactions are used in the construction of new organic molecules. The production of many man-made chemicals such as drugs, plastics, food additives, fabrics depend on organic reactions.
Class 11 Mechanical Properties of Solids MobViewManik Bhola
Type of Questions Included:
⇒ Choose the correct alternative
⇒ Conceptual questions
Topics Included:
⇒ Elastic behaviour of solids
⇒ Stress and strain
⇒ Hooke’s law
⇒ Stress-strain curve
⇒ Elastic moduli
⇒ Applications of elastic behaviour of materials.
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.
Organic reactions are chemical reactions involving organic compounds. Organic reactions are used in the construction of new organic molecules. The production of many man-made chemicals such as drugs, plastics, food additives, fabrics depend on organic reactions.
Class 11 Mechanical Properties of Solids MobViewManik Bhola
Type of Questions Included:
⇒ Choose the correct alternative
⇒ Conceptual questions
Topics Included:
⇒ Elastic behaviour of solids
⇒ Stress and strain
⇒ Hooke’s law
⇒ Stress-strain curve
⇒ Elastic moduli
⇒ Applications of elastic behaviour of materials.
What is Atom in Chemistry ?
Atom is basic building block of all matter.
Atom Have
1. Nucleus
Nucleus is very small and heavy part of the atom.
2. An Surrounding Electron Cloud
Surrounding electron cloud is large and lightweight part of the atom.
Nucleus of an Atom
Nucleus Contains
Protons
Protons have a positive charge.
All atoms are distinguished by the number of protons it has (atomic number).
Neutrons
Neutrons have no charge.
Neutrons have same mass as protons.
Electron Cloud of an Atom
An Electron Cloud of an Atom Contains
Electrons
Electron have a negative charge.
Electrons are contained within the shells of electron cloud.
Electrons have very small mass as compared to neutrons and protons.
Electron move in orbital motion around nucleus.
Electrons decides how bonds formed.
Atomic Structure
Atom is made up of Nucleus (Protons and Neutrons) and Electrons.
Prepared and Published by-
http://www.ChemistryNotesInfo.com
http://www.ChemistryNotesInfo.Blogspot.com
Read full article on what is Atom in chemistry at
https://chemistrynotesinfo.com/what-is-an-atom/
and view video of Atom at https://youtu.be/5Sdo7VKJ1uk
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 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
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
PHP Frameworks: I want to break free (IPC Berlin 2024)Ralf Eggert
In this presentation, we examine the challenges and limitations of relying too heavily on PHP frameworks in web development. We discuss the history of PHP and its frameworks to understand how this dependence has evolved. The focus will be on providing concrete tips and strategies to reduce reliance on these frameworks, based on real-world examples and practical considerations. The goal is to equip developers with the skills and knowledge to create more flexible and future-proof web applications. We'll explore the importance of maintaining autonomy in a rapidly changing tech landscape and how to make informed decisions in PHP development.
This talk is aimed at encouraging a more independent approach to using PHP frameworks, moving towards a more flexible and future-proof approach to PHP development.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
As AI technology is pushing into IT I was wondering myself, as an “infrastructure container kubernetes guy”, how get this fancy AI technology get managed from an infrastructure operational view? Is it possible to apply our lovely cloud native principals as well? What benefit’s both technologies could bring to each other?
Let me take this questions and provide you a short journey through existing deployment models and use cases for AI software. On practical examples, we discuss what cloud/on-premise strategy we may need for applying it to our own infrastructure to get it to work from an enterprise perspective. I want to give an overview about infrastructure requirements and technologies, what could be beneficial or limiting your AI use cases in an enterprise environment. An interactive Demo will give you some insides, what approaches I got already working for real.
2. Why do Covalent Bonds form?
When non-metals react with one another, their
atoms share valence electrons.
The bond formed between atoms that share electrons
is called a covalent bond.
After bonding, each atom attains the electronic
configuration of a noble gas.
2
3. What are Molecules?
When atoms combine by sharing electrons,
molecules are formed.
A molecule is a group of two or more
non-metal atoms held together by
covalent bonds.
Covalent bonds, like ionic bonds, are
STRONG bonds.
3
4. Molecules of Elements
Many non-metallic elements exist as
molecules made up of two or more identical
atoms which bond by sharing electrons in
order to become stable.
Examples:
Hydrogen (H2), chlorine (Cl2), oxygen (O2),
nitrogen (N2), fluorine (F2), bromine (Br2).
4
5. Example 1: Two hydrogen atoms share
a pair of electrons so that
Hydrogen (H2) each atom has two
electrons in its valence
shell. As a result, both
A hydrogen atom has atoms have a stable duplet
one valence electron. configuration.
H (1) H (1) H – H or H2
Single covalent bond
consisting of 2 shared 5
electrons.
6. Hydrogen
The sharing of two electrons forms a single
covalent bond.
A single covalent bond or a single bond is usually
represented by a single line ‘–’ in the structural formula.
A structural formula shows A molecular formula only
how the atoms are arranged shows the number of each
and the bond between them. kind of atom in a molecule.
6
7. Example 2:
Chlorine
A chlorine atom has seven
valence electrons.
To attain an octet structure, two chlorine
atoms combine to share a pair of electrons
(two electrons).
7
9. Oxygen
An oxygen atom has It needs two more electrons to
six valence electrons. form a stable octet structure.
Each oxygen atom shares two of its
electrons with another oxygen atom.
9
10. Oxygen
4 electrons are shared between two oxygen atoms.
Such a bond is called a double covalent bond.
O=O
A double bond is represented by ‘==’ in a structural
formula.
Q. How many electrons are shared in a double covalent
bond? 10
Four electrons (two pairs of electrons)
11. Let’s Practice!
Q. What can you deduce about the bonding
in this particle?
• It is a molecule in which the atoms are
bonded by a single covalent bond.
11
12. Let’s Practice!
Q. The valency of an atom is the number
of electrons from each atom that is shared.
What is the valency of each atom here?
One.
12
13. Let’s Practice!
Q. How many electrons are shared the a single
covalent bond?
Two.
Examples of this kind of molecule – Cl2,
F2, Br2, I2.
13
14. Let’s Practice!
Q. Give the names and molecular formulae of
molecules of the type shown here.
Fluorine (F2), chlorine (Cl2), bromine
(Br2), iodine (I2).
(Group VII elements)
14
15. Molecules of Compounds
(Molecules are always covalent, not ionic!)
When 2 or more different types of atoms form
covalent bonds, a molecular compound or
covalent compound is formed.
Water (H2O), methane (CH4),, ammonia (NH3)
and carbon dioxide (CO2)are examples of
covalent compounds.
15
16. Example 1: Water
Water is formed by the reaction of hydrogen with
oxygen such that all three atoms attain noble gas
configurations.
Each water molecule contains two single covalent bonds.
16
17. Water molecule (H2O)
+ →
The hydrogen atoms are now electronically like helium
and the oxygen atom like neon.
Two hydrogen – oxygen (H – O) 105°.
single covalent bonds are
formed.
The water molecule is V-shaped,
with the H-O-H bond angle of
105°. 17
18. Example 2: Methane
Methane (CH4) contains carbon and hydrogen.
In a methane molecule, the carbon atom has an octet
configuration while each hydrogen atom has a duplet
configuration.
Methane has four single covalent bonds.
18
20. Example 3: Ammonia, NH3
Q. How many electrons does each hydrogen atom need
to become stable? 1
Q. How many electrons does each nitrogen atom need to
become stable? 3
Ammonia molecule, NH3 (with 20
3 single covalent N-H bonds)
21. Example 4: Carbon dioxide (CO2)
8p 6p 8p
Each carbon Each
atom shares oxygen
two electrons 8p 6p 8p atom
each with shares two
two oxygen electrons.
atoms.
Two double covalent (C=O) bonds
21
22. Different ways of representing the carbon dioxide
molecule.
A carbon dioxide molecule (CO2) contains two
double covalent bonds. Each double bond has 4
shared electrons or 2 pairs of shared electrons. 22
23. Example 4: Carbon dioxide (CO2)
Each carbon atom shares two electrons each
with two oxygen atoms.
Each oxygen atom shares two electrons.
23
24. Structures of Covalent
Substances
• Simple (small)
There are 2 molecules
forms in which
covalent (2) Giant structures
substances exist:
24
25. Simple (small) Covalent
Molecules
Also known as simple molecular
structures.
Most covalent substances exist in this form
e.g.
Hydrogen (H2), Oxygen (O2), nitrogen (N2),
chlorine (N2), Iodine (I2), Methane (CH4), water
(H2O), carbon dioxide (CO2), Hydrogen
chloride (HCl), ammonia (NH3).
25
26. Ex 1: Simple Covalent Molecules
Methane (CH4)
In a molecule of methane,
CH4, the four C–H
covalent bonds are strong.
However, weak van der Waals’
forces between methane
molecules hold them together
loosely. Therefore, methane
exists as a gas at room
temperature and pressure. 26
27. Simple Covalent Molecules have low
melting & boiling points
Little energy is
needed to overcome
the weak forces
between molecules.
(In melting or boiling which are
PHYSICAL CHANGES, no
chemical bonds are broken;
e.g. in methane C-H bonds
are NOT broken).
27
28. Ex 2: Simple Covalent Molecules
Iodine (I2)
Within each iodine
molecule, the iodine atoms
are held together by strong
covalent bonds.
Between the iodine
molecules, there are
only weak van der
Waals’ forces holding
the molecules together.
Weak force 28
29. Q. Why does iodine sublime easily
when heated gently?
Sublimation is a physical
change and only bonds
between iodine molecule are
broken. The intermolecular
(van der Waals’ forces are
weak, so little energy is
needed to overcome them.
Weak force between molecules
29
30. Physical Properties of Simple
Molecular (Covalent) Compounds
1. Volatile – low melting and boiling points
2. Soluble in organic solvents; most are
insoluble in water.
3. Cannot conduct electricity in any state.
(Some exceptions are: carbon (graphite), ammonia,
ethanol, sugar, chlorine, hydrogen chloride, sulphur
dioxide.)
30
31. Q. Why are many covalent substances
liquids or gases at room temperature?
This is because of the weak van der
Waal’s forces between the molecules, so
little energy is needed to overcome them
during changes of state.
31
32. Q. Why do covalent substances not
conduct electricity even when molten
or in aqueous solution?
Covalent substances contain neutral
molecules. There are no mobile, charged ions
or electrons to conduct electricity.
(Exceptions: solid Carbon, in the form of graphite,
conducts electricity. Hydrogen chloride, sulfur
dioxide and ammonia react with water to form
solutions that conduct electricity. )
32
34. Giant Covalent (Molecular)
Structures Tetrahedral
structure
Ex 1: Diamond
It is a form (allotrope) of
carbon.
Each carbon atom
is bonded to 4 other
carbon atoms by
strong covalent
bonds.
34
36. Physical properties of diamond
1. Diamond is a very hard substance. It is not
easily scratched or worn out.
2. It has high melting point (3500°C) and high
boiling point (4800 °C).
3. Diamond does not conduct electricity.
4. It is insoluble in water.
36
37. Q. Why is Diamond hard?
A crystal of diamond contains
millions of carbon atoms joined
by strong covalent bonds.
A large amount of energy is
required to break these strong
covalent bonds. This explains
why diamond is so hard.
37
38. Q. Why is the melting point of
diamond high?
A large amount of
energy is required to
break the millions of
strong covalent
bonds so that the
atoms are separated.
38
39. Q. Why diamond does not conduct
electricity?
All the valence electrons of
the carbon atoms are used
for bonding.
There are therefore no free
electrons that are available
move through the structure to
conduct electricity.
39
40. Uses of diamond
Synthetic diamonds produced under high
pressures and temperatures are used at the
tips of drills and other cutting tools.
They are used for drilling, grinding and
polishing very hard surfaces.
40
42. Graphite - Structure
Within each layer, each
carbon atom forms strong
covalent bonds (C – C)
with three other carbon
atoms.
The atoms form rings of six
carbon atoms that are joined
together to form two-
dimensional flat layers.
Each layer is a giant molecule.
42
43. Graphite - Structure
The layers of carbon
atoms are held
together by weak van
der Waals’ forces.
Strong covalent bond (C-C)
between carbon atoms 43
44. Why does graphite have high
melting and boiling points?
In graphite, the (C-C)
bonds within each
layer are strong and
difficult to break.
Hence, graphite has high melting and boiling points.
44
45. Why is graphite soft and
slippery?
The forces of
attraction between the
layers of carbon are
very weak.
The layers can slide over
each other. This explains
why graphite is soft and
slippery.
45
46. Why is graphite able to conduct
electricity?
In graphite, each
carbon atom has one
outer (valence) shell
electron that is not
used to form covalent
bonds, and can move
through the layer to
conduct electricity!
46
47. Why is graphite able to conduct
electricity?
These electrons are
delocalised (free) , that
is, they can move along
the layers from one
carbon atom to the next
when graphite is
connected to a battery.
Hence, graphite is a good conductor of electricity.
47
48. Uses of graphite
1. As a dry lubricant.
2. As brushes for electric motors (to reduce
friction).
3. To make inert electrodes for electrolysis.
4. Baked with clay to make pencil lead.
48
49. Silicon (IV) oxide
Sand is actually silicon
(IV) oxide.
It is also commonly
known as silica.
The formula of silicon
(IV) oxide is SiO2. It
is also known as
silicon dioxide.
49
50. Silicon (IV) oxide - structure
Each silicon atom is
bonded to four oxygen
atoms in a tetrahedral
structure and
each oxygen atom is
bonded to two silicon
atoms.
50
51. Why does Silicon (IV) oxide
have a high melting point?
This is because the silicon and
oxygen atoms are all held together
by strong covalent bonds in a giant
covalent (molecular) structure.
51
52. Writing the formulae of covalent
compounds
Ex 1:
What is the chemical formula of carbon dioxide?
We assume the first element named (carbon)
contains only one atom unless otherwise stated.
The word ‘dioxide’ means ‘two oxygen atoms’.
So the formula is CO2.
52
53. Ex 2: What is the chemical formula
of dinitrogen monoxide?
Dinitrogen means 2 nitrogen atoms.
Monoxide means 1 oxygen atom.
So the formula is N2O.
53
54. Ex 3: What is the chemical formula
of dinitrogen tetroxide?
Dinitrogen means 2 nitrogen atoms.
Tetroxide means 4 oxygen atoms.
So the formula is N2O4.
54
55. Formulae of covalent substances are not
always so easily derived.
Chemical formulae of some common covalent
substances which cannot be derived from their
names include:
ammonia (NH3),
hydrogen peroxide (H2O2),
methane (CH4),
ozone (O3),
water (H2O).
55