This document discusses covalent bonding and molecular compounds. It begins by explaining that HCl and H2O are molecular compounds because their atoms share electrons through covalent bonds rather than transferring electrons. Molecular compounds have lower melting and boiling points than ionic compounds. The molecular formula shows the types and numbers of atoms in a molecule but not its structure. Covalent bonds form when atoms share electron pairs to achieve noble gas configurations. Single, double and triple covalent bonds are formed by sharing one, two or three electron pairs respectively. Coordinate covalent bonds have one atom donating both bonding electrons. Ozone's bonding structure involves resonance forms with equivalent arrangements of electron pairs.
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 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.
Chapter 6: Chemical Bonding, Modern Chemistry. This is a working presentation of the notes for this chapter. Meaning that we may or may not cover all of the material here.
This slides demonstrate on the formation of positive and negative ions, followed by formation of ionic bonding and covalent bonding. Chemical bonding have various types of bonding. In the presentation, we're sharing only ionic and covalent bonding only.
For Chem 1:
Significanceof the ELectron in Bonding
The Octet Rule
Lewis Symbol/Structures
Formal Charge
Polyatomic Ions
Types of Bonds (Ionic, Covalent, Coordinate Covalent, Metallic Bonds, Multiple Bonds)
Exceptions to the Octet Rules
Oxidation Number is not included in the class discussion and exam. ;D
It's very good for SPM students . You have to learn the ionic bond thoroughly. If you understand well you can explain it vividly. For other chemistry notes can email me puterizamrud@gmail.com or facebook Pusat Tuisyen Zamrud .
Chapter 6: Chemical Bonding, Modern Chemistry. This is a working presentation of the notes for this chapter. Meaning that we may or may not cover all of the material here.
This slides demonstrate on the formation of positive and negative ions, followed by formation of ionic bonding and covalent bonding. Chemical bonding have various types of bonding. In the presentation, we're sharing only ionic and covalent bonding only.
For Chem 1:
Significanceof the ELectron in Bonding
The Octet Rule
Lewis Symbol/Structures
Formal Charge
Polyatomic Ions
Types of Bonds (Ionic, Covalent, Coordinate Covalent, Metallic Bonds, Multiple Bonds)
Exceptions to the Octet Rules
Oxidation Number is not included in the class discussion and exam. ;D
It's very good for SPM students . You have to learn the ionic bond thoroughly. If you understand well you can explain it vividly. For other chemistry notes can email me puterizamrud@gmail.com or facebook Pusat Tuisyen Zamrud .
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 increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Richard's entangled aventures in wonderlandRichard 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.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
2. Are HCl (hydrochloric acid) and (H2O) water ionic compounds?
These compounds are not ionic, because their atoms do not
give or accept electrons, they held together by sharing
electrons forming a covalent bond.
Some elements found in nature in the form of molecules.
Molecule
A neutral group of atoms joined together by covalent bonds.
e.g. oxygen molecule is a diatomic molecule because it
consists of two atoms joined together by a covalent bond.
Diatomic molecule: is a molecule consists of two atoms.
If a compound is composed of molecules is called,
molecular compound.
So HCl (hydrochloric acid) and H2O (water) are molecular
compounds
2
3. Molecular compounds have lower melting and boiling points
than ionic compounds.
Characteristics of molecular compounds:
o Low melting and boiling points.
o many compounds are gases and liquids at room temperature.
Molecular Formula
The chemical formula of a molecular compound.
It shows how many atoms of each element a molecule contains.
• Write the molecular formula for water.
• How many elements are there in water molecule?
• How many atoms are there in water molecule?
• Is water ionic or molecular compound?
e.g.
3
7. In covalent bonds, electron sharing usually occurs so that
atoms attain the electron configurations of noble gases.
Single Covalent Bond
is a bond joining two atoms by sharing one pair of electrons.
e.g. hydrogen gas consists of diatomic molecules whose
atoms share only one pair of electrons, forming a single
covalent bond.
An electron dot
structure such as
represents
the shared pair of
electrons of the
covalent bond by
two dots.
H:H
7
8. Structural Formula represents the covalent bonds by
dashes and shows the arrangement of covalently bonded
atoms.
All halogens form covalent single bonds in their diatomic
molecules.
because a halogen has seven valence electrons, so it needs
one more to attain the electron configuration of a noble gas.
8
9. Each fluorine atom contributes one electron to complete the
octet.
The pair of valence electrons that is not shared between
atoms is called, Unshared Pair.
e.g. Fluorine atom has seven valence electrons. By sharing
electrons and forming a single covalent bond, two fluorine
atoms achieve the electron configuration of neon.
9
10. e.g. (H2O) water is a molecule containing three atoms with
two single covalent bonds. Two hydrogen atoms share
electrons with one oxygen atom.
The hydrogen and oxygen atom attain noble-gas
configurations by sharing electrons.
The oxygen atom in water has two unshared
pairs of valence electrons.
10
11. e.g. NH3 (ammonia) has 3 single covalent bonds with
unshared pair of electrons.
11
12. e.g. CH4 (Methane) has 4 single covalent bonds with
no unshared pair of electrons.
12
13. Double and Triple Covalent Bonds
A bond formed by sharing two pairs of electrons is called,
double covalent bond.
13
14. A bond formed by sharing three pairs of electrons is called,
triple covalent bond.
14
15. Sometimes a molecule can not attain the octet rule by
single, double or triple covalent bonds.
e.g. In carbon monoxide molecule, oxygen has a stable
configuration while the carbon does not.
To solve this problem, oxygen
donates one its unshared
electrons of electrons for
bonding.
15
16. Coordinate Covalent Bond is a covalent bond in which one
atom contributes both bonding electrons.
It can be shown in structural formula as an arrow that
points from the atom donating the pair of electrons to the
atom receiving them.
In a coordinate covalent bond, the shared electron pair
comes from one of the bonding atoms.
16
17. e.g. NH4
+ (ammonium ion) consists of atoms joined by
covalent bonds, including coordinate covalent bond.
The ammonium ion forms when charged hydrogen ion (H+)
attaches to the unshared pair of an ammonia molecule (NH3).
Polyatomic ion is a tightly bound group of atoms that has
a positive or negative charge and behaves as a unit.
17
18. Write the electron dot structure of Ozone.
Notice that the structure on the left can be converted to
the one on the right by shifting electron pairs without
changing the positions of the oxygen atoms.
The actual bonding of oxygen atoms in ozone is a hybrid, or
mixture, of the extremes represented by the resonance
forms.
Resonance structure: is a structure that occurs when it is
possible to draw two or more valid electron dot structures
that have the same number of electron pairs for a molecule
or ion.
18