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Slater's rules provide a method to estimate the shielding of electrons and the effective nuclear charge experienced by electrons in an atom. The rules involve writing the electron configuration, ignoring higher energy level electrons, and applying shielding constants of 0.35 for electrons in the same subshell and 0.85 for electrons in the previous subshell. As an example, the rules are used to calculate that the effective nuclear charge experienced by the valence electrons of nitrogen is 3.9 instead of the actual nuclear charge of 7.
Crystal Field Theory explains the colors of transition metal complexes based on ligand-metal interactions. The electrostatic interaction between ligands and metal d-orbitals splits the d-orbital energies. For an octahedral complex, the d-orbitals point directly at ligands have higher energy than those that bisect ligands. This splitting pattern determines if the complex is high or low spin, which then dictates its color and magnetic properties. The spectrochemical series orders ligands by their ability to cause crystal field splitting, correlating ligand type with complex color.
The document summarizes key points about crystal field theory and its application to octahedral complexes. It discusses the historical development of metal complexes, assumptions of crystal field theory, and how it can be applied to explain splitting of d-orbitals in an octahedral complex. It also examines factors that affect crystal field stabilization energy, including the nature of the metal ion and ligands. Finally, it describes how crystal field theory can be used to understand the color and magnetic properties of complexes.
d-block elements are those in which the valence electrons enters the d orbital. d- block elements are also called transition elements. Transition elements have partially filled d orbitals.
this presentation discusses the crystal field theory and its role in explaining the formation of coordination complexes by transition elements, their magnetic and colour properties; and its limitations!
This document discusses Werner's theory of coordination compounds and bonding in coordination compounds. According to Werner's theory, metal atoms in coordination compounds have both primary and secondary valencies. Primary valencies are ionizable and satisfy the compound's oxidation state, while secondary valencies are non-ionizable and satisfy the compound's coordination number through coordinate covalent bonds with electron pair donors like ligands. The document also discusses Sidgwick's effective atomic number rule and how the valence bond theory explains the geometry, hybridization, and magnetic properties of coordination compounds.
Slater's rules provide a method to estimate the shielding of electrons and the effective nuclear charge experienced by electrons in an atom. The rules involve writing the electron configuration, ignoring higher energy level electrons, and applying shielding constants of 0.35 for electrons in the same subshell and 0.85 for electrons in the previous subshell. As an example, the rules are used to calculate that the effective nuclear charge experienced by the valence electrons of nitrogen is 3.9 instead of the actual nuclear charge of 7.
Crystal Field Theory explains the colors of transition metal complexes based on ligand-metal interactions. The electrostatic interaction between ligands and metal d-orbitals splits the d-orbital energies. For an octahedral complex, the d-orbitals point directly at ligands have higher energy than those that bisect ligands. This splitting pattern determines if the complex is high or low spin, which then dictates its color and magnetic properties. The spectrochemical series orders ligands by their ability to cause crystal field splitting, correlating ligand type with complex color.
The document summarizes key points about crystal field theory and its application to octahedral complexes. It discusses the historical development of metal complexes, assumptions of crystal field theory, and how it can be applied to explain splitting of d-orbitals in an octahedral complex. It also examines factors that affect crystal field stabilization energy, including the nature of the metal ion and ligands. Finally, it describes how crystal field theory can be used to understand the color and magnetic properties of complexes.
d-block elements are those in which the valence electrons enters the d orbital. d- block elements are also called transition elements. Transition elements have partially filled d orbitals.
this presentation discusses the crystal field theory and its role in explaining the formation of coordination complexes by transition elements, their magnetic and colour properties; and its limitations!
This document discusses Werner's theory of coordination compounds and bonding in coordination compounds. According to Werner's theory, metal atoms in coordination compounds have both primary and secondary valencies. Primary valencies are ionizable and satisfy the compound's oxidation state, while secondary valencies are non-ionizable and satisfy the compound's coordination number through coordinate covalent bonds with electron pair donors like ligands. The document also discusses Sidgwick's effective atomic number rule and how the valence bond theory explains the geometry, hybridization, and magnetic properties of coordination compounds.
The document discusses inner transition elements, specifically the lanthanide and actinide series. It provides details on their electronic configurations, oxidation states, properties such as color and magnetism, extraction from monazite sand, and separation methods. It also compares the lanthanides and actinides, noting they both show lanthanide/actinide contractions and have similar properties, but the actinides exhibit more variable chemistry and are all radioactive.
Theories of coordination compounds, CFSE, Bonding in octahedral and tetrahedral complex, color of transition metal complex, magnetic properties, selection rules, Nephelxeuatic effect, angular overlap model
Crystal field theory and ligand field theory describe how ligands interact with transition metal complexes. Crystal field theory uses an electrostatic model to explain orbital splitting, while ligand field theory uses a molecular orbital approach. Both theories predict that ligands cause the d orbitals on the metal to split into lower energy t2g and higher energy eg sets. The size of this splitting depends on whether ligands are σ-donors only, π-donors, or π-acceptors. π-Acceptors increase splitting while π-donors decrease it. This explains the spectrochemical series from weak to strong field ligands.
This document summarizes Crystal Field Theory, which considers the electrostatic interactions between metal ions and ligands. It describes ligands and metal ions as point charges that can have attractive or repulsive forces. This causes the d orbitals of the metal ion to split into two sets depending on if the field created by the ligands is weak or strong. The theory explains color in coordination compounds as being caused by d-d electron transitions under the influence of ligands. However, it has limitations like not accounting for other metal orbitals or the partial covalent nature of metal-ligand bonds.
The following questions answers are as under:-
What is the valence bond theory?
What are the shortcomings of VBT?
What are the merits of the valence bond theory?
Crystal field theory proposes that ligands behave as point charges that create an electric field around a central metal ion. This affects the energies of the metal's d-orbitals. In an octahedral complex, ligands along the x, y, and z axes interact more strongly with the dz2 and dx2-y2 orbitals, splitting them into the higher-energy eg set. The dxy, dyz, and dxz orbitals interact less with ligands between the axes, forming the lower-energy t2g set. This splitting of orbital energies, described by the crystal field splitting parameter Δ0, helps explain differences in complexes' magnetic properties.
The document discusses the lanthanide series of f-block elements. It provides the electronic configurations of the lanthanide elements from Lanthanum to Lutetium. It describes the lanthanide contraction effect where atomic and ionic radii decrease across the series. Key effects of lanthanide contraction include decreased basicity and similar ionic radii of post-lanthanide elements to those in the previous period. The document also briefly introduces the actinide series and notes their similar properties to lanthanides but with 5f electrons instead of 4f.
This document discusses coordination compounds and Werner's theory of coordination compounds. It provides details on:
- Coordination compounds are molecular compounds where a central metal atom is bound to surrounding ligands by dative bonds.
- Werner's theory successfully explained the structure and bonding in coordination compounds using the concept of primary and secondary valencies on the metal center.
- Some limitations of Werner's theory are that it does not explain factors influencing complex stability or the directional properties of bonds in complexes.
This document discusses crystal field theory (CFT), which interprets the chemistry of coordination compounds. Some key points:
1. CFT was proposed by Hans Bethe in 1929 and modified by J.H. Van Vleck in 1935 to allow for some covalency. It assumes electrostatic interactions between metal ions and ligands.
2. In an octahedral crystal field, the d-orbitals split into two sets - the lower energy t2g orbitals and higher energy eg orbitals. The splitting is called the crystal field splitting parameter Δo.
3. The color of coordination compounds depends on the size of this splitting, as the energy difference corresponds to the absorption of photons.
The spectrochemical series arranges ligands in order of their crystal field splitting parameter (Δ), which indicates their ability to repel electrons in a metal-ligand complex. Strong field ligands like cyanide cause large Δ and greater splitting of d-orbital energies. In an octahedral complex, strong field ligands create a large energy gap between the lower-energy t2g and higher-energy eg orbitals, forcing electrons into the lower t2g orbitals and producing a complex with low spin. Weak field ligands like halides cause small Δ and less splitting, allowing electrons to fill orbitals normally and producing a high-spin complex. The type of ligand affects the splitting of orbitals and spin state in transition
Nonstoichiometric or Berthollide compounds have ratios of atoms that are not whole numbers as implied by the chemical formula. There are several types of defects that can occur in nonstoichiometric compounds including negative ions being absent, interstitial ions and electrons, positive ions being absent, and extra interstitial negative ions. These defects can cause the compounds to act as n-type or p-type semiconductors depending on whether there is a metal excess or deficiency.
The document discusses the lanthanides and actinides, which are groups of elements found below the main periodic table. There are a total of 30 elements between the lanthanides (elements 57-71) and actinides (elements 89-103). The lanthanides and actinides are often referred to as the "inner transition metals" and exhibit similar chemical properties to lanthanum and actinium, respectively.
The document summarizes key information about d-block and f-block elements. It discusses:
- The d-block elements have their d orbitals progressively filled in each period, while the f-block elements have their 4f and 5f orbitals filled in the latter two periods.
- Transition metals exhibit a variety of oxidation states, melting points, atomic radii, and magnetic properties due to their incompletely filled d orbitals.
- Properties vary periodically across each series as the nuclear charge increases, with factors like ionization energies and electronegativity influencing stability and reactivity.
The document discusses the modern periodic law and periodic trends in atomic properties. It can be summarized as follows:
1. The modern periodic law states that the properties of elements are periodic functions of their atomic numbers. Elements are arranged in the periodic table based on increasing atomic number and similar outer electron configurations that repeat at regular intervals.
2. The periodic table is divided into blocks based on orbital types. Elements show trends in properties within periods and down groups, including decreasing atomic radius and increasing ionization energy with increasing atomic number. Electron affinity also tends to decrease down groups.
3. Successive ionization energies increase as more energy is required to remove additional electrons. Stability of half-filled and fully-filled
This document discusses the key concepts from Chapter 14 of the chemistry textbook. It covers d-block and f-block elements in the periodic table, including their electronic structures, properties, and important reactions. The chapter is divided into several sections, including an introduction to periodic table, transition elements, general features of transition elements, coordination compounds, and the chemistry of some important transition elements such as vanadium, chromium, manganese, iron and copper.
This document provides an overview of coordination compounds. It begins by defining coordination compounds as those containing metal ions bonded to other neutral or negatively charged molecules by coordinate bonds. It then discusses various topics relating to coordination compounds, including Werner's theory of coordination chemistry, ligands, nomenclature, isomerism, and more. Key aspects covered include the defining characteristics and components of coordination compounds and complexes, common ligands, Werner's postulates explaining the electronic structure of complexes, and methods for naming coordination compounds according to IUPAC rules.
actinide complexes and uses, Inorganic chemistryRabia Aziz
more chemistry contents are available
1. pdf file on Termmate: https://www.termmate.com/rabia.aziz
2. YouTube: https://www.youtube.com/channel/UCKxWnNdskGHnZFS0h1QRTEA
3. Facebook: https://web.facebook.com/Chemist.Rabia.Aziz/
4. Blogger: https://chemistry-academy.blogspot.com/
actinide complexes and uses
This document discusses transition series elements and their properties. It describes how transition elements have electrons that enter the (n-1)d orbitals, giving them variable oxidation states up to +8. Their atomic radii decrease across periods but increase down groups. Transition metals can conduct heat and electricity well and can be alloyed to improve strength. Some have magnetic properties depending on unpaired electrons. Their colored complexes are due to electron transitions between d orbitals. Common applications include stainless steel, bronze, and uses of copper and nickel in coins, batteries, and turbines.
This document discusses coordination chemistry and isomerism in coordination compounds. It defines molecular compounds, complex salts, and double salts formed from combinations of inorganic salts. It also discusses ligands, classifying them based on properties. Coordination number and the resulting geometries for coordination numbers 2 through 9 are described. Finally, it outlines different types of isomerism that can occur in coordination compounds, including structural, spin, and stereo isomerism.
CRYSTAL FIELD THEORY OCTAHEDRAL SPLITTING.pptxMushiraBanu
In coordination Chemistry, The CFT theory plays an important role... The splitting of Octahedral Complexes is neatly described in this presentation......
This document provides an overview of transition metal coordination chemistry. It discusses the following key points in 3 sentences or less:
Metal complexes consist of a central metal ion bonded to surrounding ligand molecules or ions. The ligands donate lone pairs of electrons to form coordinate covalent bonds with the metal. The geometry and electronic structure of complexes is influenced by the coordination number, ligands present, and hybridization state of the metal ion.
The document discusses inner transition elements, specifically the lanthanide and actinide series. It provides details on their electronic configurations, oxidation states, properties such as color and magnetism, extraction from monazite sand, and separation methods. It also compares the lanthanides and actinides, noting they both show lanthanide/actinide contractions and have similar properties, but the actinides exhibit more variable chemistry and are all radioactive.
Theories of coordination compounds, CFSE, Bonding in octahedral and tetrahedral complex, color of transition metal complex, magnetic properties, selection rules, Nephelxeuatic effect, angular overlap model
Crystal field theory and ligand field theory describe how ligands interact with transition metal complexes. Crystal field theory uses an electrostatic model to explain orbital splitting, while ligand field theory uses a molecular orbital approach. Both theories predict that ligands cause the d orbitals on the metal to split into lower energy t2g and higher energy eg sets. The size of this splitting depends on whether ligands are σ-donors only, π-donors, or π-acceptors. π-Acceptors increase splitting while π-donors decrease it. This explains the spectrochemical series from weak to strong field ligands.
This document summarizes Crystal Field Theory, which considers the electrostatic interactions between metal ions and ligands. It describes ligands and metal ions as point charges that can have attractive or repulsive forces. This causes the d orbitals of the metal ion to split into two sets depending on if the field created by the ligands is weak or strong. The theory explains color in coordination compounds as being caused by d-d electron transitions under the influence of ligands. However, it has limitations like not accounting for other metal orbitals or the partial covalent nature of metal-ligand bonds.
The following questions answers are as under:-
What is the valence bond theory?
What are the shortcomings of VBT?
What are the merits of the valence bond theory?
Crystal field theory proposes that ligands behave as point charges that create an electric field around a central metal ion. This affects the energies of the metal's d-orbitals. In an octahedral complex, ligands along the x, y, and z axes interact more strongly with the dz2 and dx2-y2 orbitals, splitting them into the higher-energy eg set. The dxy, dyz, and dxz orbitals interact less with ligands between the axes, forming the lower-energy t2g set. This splitting of orbital energies, described by the crystal field splitting parameter Δ0, helps explain differences in complexes' magnetic properties.
The document discusses the lanthanide series of f-block elements. It provides the electronic configurations of the lanthanide elements from Lanthanum to Lutetium. It describes the lanthanide contraction effect where atomic and ionic radii decrease across the series. Key effects of lanthanide contraction include decreased basicity and similar ionic radii of post-lanthanide elements to those in the previous period. The document also briefly introduces the actinide series and notes their similar properties to lanthanides but with 5f electrons instead of 4f.
This document discusses coordination compounds and Werner's theory of coordination compounds. It provides details on:
- Coordination compounds are molecular compounds where a central metal atom is bound to surrounding ligands by dative bonds.
- Werner's theory successfully explained the structure and bonding in coordination compounds using the concept of primary and secondary valencies on the metal center.
- Some limitations of Werner's theory are that it does not explain factors influencing complex stability or the directional properties of bonds in complexes.
This document discusses crystal field theory (CFT), which interprets the chemistry of coordination compounds. Some key points:
1. CFT was proposed by Hans Bethe in 1929 and modified by J.H. Van Vleck in 1935 to allow for some covalency. It assumes electrostatic interactions between metal ions and ligands.
2. In an octahedral crystal field, the d-orbitals split into two sets - the lower energy t2g orbitals and higher energy eg orbitals. The splitting is called the crystal field splitting parameter Δo.
3. The color of coordination compounds depends on the size of this splitting, as the energy difference corresponds to the absorption of photons.
The spectrochemical series arranges ligands in order of their crystal field splitting parameter (Δ), which indicates their ability to repel electrons in a metal-ligand complex. Strong field ligands like cyanide cause large Δ and greater splitting of d-orbital energies. In an octahedral complex, strong field ligands create a large energy gap between the lower-energy t2g and higher-energy eg orbitals, forcing electrons into the lower t2g orbitals and producing a complex with low spin. Weak field ligands like halides cause small Δ and less splitting, allowing electrons to fill orbitals normally and producing a high-spin complex. The type of ligand affects the splitting of orbitals and spin state in transition
Nonstoichiometric or Berthollide compounds have ratios of atoms that are not whole numbers as implied by the chemical formula. There are several types of defects that can occur in nonstoichiometric compounds including negative ions being absent, interstitial ions and electrons, positive ions being absent, and extra interstitial negative ions. These defects can cause the compounds to act as n-type or p-type semiconductors depending on whether there is a metal excess or deficiency.
The document discusses the lanthanides and actinides, which are groups of elements found below the main periodic table. There are a total of 30 elements between the lanthanides (elements 57-71) and actinides (elements 89-103). The lanthanides and actinides are often referred to as the "inner transition metals" and exhibit similar chemical properties to lanthanum and actinium, respectively.
The document summarizes key information about d-block and f-block elements. It discusses:
- The d-block elements have their d orbitals progressively filled in each period, while the f-block elements have their 4f and 5f orbitals filled in the latter two periods.
- Transition metals exhibit a variety of oxidation states, melting points, atomic radii, and magnetic properties due to their incompletely filled d orbitals.
- Properties vary periodically across each series as the nuclear charge increases, with factors like ionization energies and electronegativity influencing stability and reactivity.
The document discusses the modern periodic law and periodic trends in atomic properties. It can be summarized as follows:
1. The modern periodic law states that the properties of elements are periodic functions of their atomic numbers. Elements are arranged in the periodic table based on increasing atomic number and similar outer electron configurations that repeat at regular intervals.
2. The periodic table is divided into blocks based on orbital types. Elements show trends in properties within periods and down groups, including decreasing atomic radius and increasing ionization energy with increasing atomic number. Electron affinity also tends to decrease down groups.
3. Successive ionization energies increase as more energy is required to remove additional electrons. Stability of half-filled and fully-filled
This document discusses the key concepts from Chapter 14 of the chemistry textbook. It covers d-block and f-block elements in the periodic table, including their electronic structures, properties, and important reactions. The chapter is divided into several sections, including an introduction to periodic table, transition elements, general features of transition elements, coordination compounds, and the chemistry of some important transition elements such as vanadium, chromium, manganese, iron and copper.
This document provides an overview of coordination compounds. It begins by defining coordination compounds as those containing metal ions bonded to other neutral or negatively charged molecules by coordinate bonds. It then discusses various topics relating to coordination compounds, including Werner's theory of coordination chemistry, ligands, nomenclature, isomerism, and more. Key aspects covered include the defining characteristics and components of coordination compounds and complexes, common ligands, Werner's postulates explaining the electronic structure of complexes, and methods for naming coordination compounds according to IUPAC rules.
actinide complexes and uses, Inorganic chemistryRabia Aziz
more chemistry contents are available
1. pdf file on Termmate: https://www.termmate.com/rabia.aziz
2. YouTube: https://www.youtube.com/channel/UCKxWnNdskGHnZFS0h1QRTEA
3. Facebook: https://web.facebook.com/Chemist.Rabia.Aziz/
4. Blogger: https://chemistry-academy.blogspot.com/
actinide complexes and uses
This document discusses transition series elements and their properties. It describes how transition elements have electrons that enter the (n-1)d orbitals, giving them variable oxidation states up to +8. Their atomic radii decrease across periods but increase down groups. Transition metals can conduct heat and electricity well and can be alloyed to improve strength. Some have magnetic properties depending on unpaired electrons. Their colored complexes are due to electron transitions between d orbitals. Common applications include stainless steel, bronze, and uses of copper and nickel in coins, batteries, and turbines.
This document discusses coordination chemistry and isomerism in coordination compounds. It defines molecular compounds, complex salts, and double salts formed from combinations of inorganic salts. It also discusses ligands, classifying them based on properties. Coordination number and the resulting geometries for coordination numbers 2 through 9 are described. Finally, it outlines different types of isomerism that can occur in coordination compounds, including structural, spin, and stereo isomerism.
CRYSTAL FIELD THEORY OCTAHEDRAL SPLITTING.pptxMushiraBanu
In coordination Chemistry, The CFT theory plays an important role... The splitting of Octahedral Complexes is neatly described in this presentation......
This document provides an overview of transition metal coordination chemistry. It discusses the following key points in 3 sentences or less:
Metal complexes consist of a central metal ion bonded to surrounding ligand molecules or ions. The ligands donate lone pairs of electrons to form coordinate covalent bonds with the metal. The geometry and electronic structure of complexes is influenced by the coordination number, ligands present, and hybridization state of the metal ion.
- The document discusses the structure of the atom, beginning with John Dalton's model of indivisible atoms and progressing to modern atomic structure based on experiments like Rutherford's gold foil experiment.
- It describes subatomic particles like electrons, protons, and neutrons that make up atoms, and models of atomic structure proposed by scientists like Thomson, Rutherford, Bohr, and Moseley.
- Key aspects of atomic structure covered include the Bohr model of electron orbits, calculation of orbital radii and velocities, and the relationship between potential energy, kinetic energy and total energy of electrons in atoms.
This document discusses different types of chemical bonds:
1) Metallic bonds form when valence electrons are delocalized and shared between all metal atoms in a lattice, holding the positive ions together.
2) Ionic bonds form when a metal transfers electrons to a nonmetal, creating oppositely charged ions that are attracted to each other.
3) Covalent bonds form when two nonmetals share valence electrons in a molecule through electron pairs. Lewis structures are used to represent electron sharing in covalent bonds.
1) The document discusses the topic-structure of an atom and summarizes the key discoveries that led to modern atomic theory, including the discovery of the electron, proton, neutron, and development of atomic models.
2) It describes Michael Faraday's experiments in the 1830s that provided early insights into atomic structure and the discovery of the electron in the 1850s from cathode ray experiments.
3) The document also summarizes Bohr's 1913 model of the hydrogen atom which explained its spectral lines by postulating stable electron orbits, and the development of quantum mechanics and Schrodinger's equation to more fully describe atomic structure.
Coordination Chemistry, Fundamental Concepts and TheoriesImtiaz Alam
This document provides an overview of coordination chemistry concepts including:
- Werner's coordination theory which proposed that metals exhibit primary and secondary valences.
- Blomstrand-Jorgensen chain theory which suggested cobalt(III) forms complexes with only three bonds.
- Nomenclature rules for naming coordination compounds based on ligands and metal oxidation state.
- Crystal field theory which explains color and magnetic properties of complexes based on ligand effects on d orbital splitting.
- The distinction between labile complexes with rapidly substituting ligands versus inert complexes.
- Coordination compounds are important as they are present in chlorophyll and hemoglobin. They allow for photosynthesis and oxygen transport.
- Coordination compounds consist of a central metal ion bonded to surrounding ligand molecules or ions.
- Werner's theory explained that the metal ion has both a primary valency based on its oxidation state and a secondary valency equal to its coordination number. The coordination number determines the compound's geometry.
- Atoms consist of electrons surrounding a positively charged nucleus made up of protons and neutrons. Different types of atoms have different numbers of protons, electrons, and neutrons.
- There are two main types of chemical bonding: ionic bonding and covalent bonding. Ionic bonding involves the transfer of electrons between atoms to form oppositely charged ions that are attracted to each other. Covalent bonding involves the sharing of electrons between atoms.
- Covalent bonding allows for many different molecular structures and isomers. Molecules can be nonpolar or polar depending on electron distribution. Metals exhibit metallic bonding where electrons are delocalized and shared among many neighboring atoms. Hydrogen bonding is a weaker interaction between polar molecules that
This document discusses atomic structure and electron configuration. It contains the following key points:
1. Atoms are made up of protons, neutrons, and electrons, with protons and neutrons located in the nucleus and electrons orbiting the nucleus.
2. Electrons can occupy different energy levels characterized by quantum numbers like principal quantum number and azimuthal quantum number. This determines the shape of electron orbitals.
3. The electron configuration of an atom shows the distribution of electrons among these orbitals, following the Pauli exclusion principle. Valence electrons are in the outermost shell and influence chemical bonding and properties.
4. Elements are arranged in the periodic table based on their atomic structure, including number
This document discusses periodicity and trends in properties across and down periods of the periodic table. It explains that atomic radius generally decreases across periods as nuclear charge increases, outweighing constant screening effects. Atomic radius increases down groups as nuclear charge rises but screening effects also increase. Ionic radius follows similar trends as atomic radius but is smaller for cations and larger for anions. Melting and boiling points are influenced by type and strength of bonding. Metallic bonding results in higher melting points for metals with more delocalized electrons. Network covalent bonding in nonmetals produces high melting points due to needing to overcome many bonds. Molecular nonmetals have weaker van der Waals forces between molecules. First ionization energies also follow trends
Chemical bonds form through ionic or covalent bonding. Ionic bonding occurs when an atom transfers an electron to another atom, forming oppositely charged ions that are attracted to each other. Covalent bonding occurs when atoms share electrons equally. Ionic bonds are generally stronger than covalent bonds due to the electrostatic forces of attraction between ions. Examples of ionic compounds include sodium chloride and magnesium fluoride, while examples of covalent compounds include phosphorus trichloride.
Chemical bonds form through different types of attractions between atoms. Ionic bonds form when electrons are transferred from one atom to another, creating oppositely charged ions that are attracted to each other. Covalent bonds form when atoms share electrons equally. Ionic bonds are generally stronger than covalent bonds because more energy is required to overcome the electrostatic forces between ions.
The document discusses the theory of coordination compounds. It defines coordination compounds as products of Lewis acid-base reactions where ligands bond to a central metal atom via coordinate covalent bonds. It describes coordination bonds and terminology like ligands, central metal ion, oxidation state, and coordination number. The document also discusses Werner's theory of coordination complexes, valence bond theory, types of ligands, nomenclature of coordination compounds, and limitations of Werner's theory.
1. The document discusses atomic structure and bonding. It describes the structure of atoms in terms of electrons and the nucleus containing protons and neutrons. It also discusses the arrangement of electrons in shells and the significance of noble gas structures and valency electrons.
2. The document then covers the periodic table and periodic trends. It defines properties such as atomic number, mass number, and isotopes. It explains how the periodic table is arranged based on these properties and how elements in the same group have similar properties.
3. The types of bonding are described including ionic bonding between metals and non-metals which forms ionic lattices, and covalent bonding between non-metals which forms molecules by sharing electron
1. There are three main types of primary bonding: ionic, covalent, and metallic. Ionic bonding involves the transfer of electrons between atoms. Covalent bonding involves the sharing of electrons between atoms. Metallic bonding involves delocalized electrons that act as a "sea" or "glue" between positively charged metal ions.
2. In addition to primary bonds, there can also be secondary bonding interactions between molecules called van der Waals forces. These weaker interactions influence physical properties.
3. Crystal structure, bonding type, and defects all impact a material's properties. Ionic and covalent materials have large bond energies and are brittle with high melting points, while metallic materials have variable bond energies and
The term Lewis acid refers to a definition of aci.pdfannaelctronics
The term Lewis acid refers to a definition of acid published by Gilbert N. Lewis in
1923, specifically: An acid substance is one which can employ an electron lone pair from another
molecule in completing the stable group of one of its own atoms.[1] Thus, H+ is a Lewis acid,
since it can accept a lone pair, completing its stable form, which requires two electrons. The
modern-day definition of Lewis acid, as given by IUPAC is a molecular entity (and the
corresponding chemical species) that is an electron-pair acceptor and therefore able to react with
a Lewis base to form a Lewis adduct, by sharing the electron pair furnished by the Lewis
base.[2] This definition is both more general and more specific—the electron pair need not be a
lone pair (it could be the pair of electrons in a p bond, for example), but the reaction should give
an adduct (and not just be a displacement reaction). Crystal field theory (CFT) is a model that
describes the breaking of degeneracies of electronic orbital states, usually d or f orbitals, due to a
static electric field produced by a surrounding charge distribution (anion neighbors). This theory
has been used to describe various spectroscopies of transition metal coordination complexes, in
particular optical spectra (colours). CFT successfully accounts for some magnetic properties,
colours, hydration enthalpies, and spinel structures of transition metal complexes, but it does not
attempt to describe bonding. CFT was developed by physicists Hans Bethe and John Hasbrouck
van Vleck[1] in the 1930s. CFT was subsequently combined with molecular orbital theory to
form the more realistic and complex ligand field theory (LFT), which delivers insight into the
process of chemical bonding in transition metal complexes. In chemistry, valence bond (VB)
theory is one of two basic theories, along with molecular orbital (MO) theory, that were
developed to use the methods of quantum mechanics to explain chemical bonding. It focuses on
how the atomic orbitals of the dissociated atoms combine to give individual chemical bonds
when a molecule is formed. In contrast, molecular orbital theory has orbitals that cover the whole
molecule.
Solution
The term Lewis acid refers to a definition of acid published by Gilbert N. Lewis in
1923, specifically: An acid substance is one which can employ an electron lone pair from another
molecule in completing the stable group of one of its own atoms.[1] Thus, H+ is a Lewis acid,
since it can accept a lone pair, completing its stable form, which requires two electrons. The
modern-day definition of Lewis acid, as given by IUPAC is a molecular entity (and the
corresponding chemical species) that is an electron-pair acceptor and therefore able to react with
a Lewis base to form a Lewis adduct, by sharing the electron pair furnished by the Lewis
base.[2] This definition is both more general and more specific—the electron pair need not be a
lone pair (it could be the pair of electrons in a p bond, for example.
The document discusses the properties of metals and their crystalline structure. It begins by explaining that metals have a closely packed crystalline structure, usually face centered cubic, body centered cubic, or hexagonal close packed. This gives metals their high conductivity of heat and electricity as well as their malleability, ductility, and high melting and boiling points. Metals also have metallic luster and can emit electrons through thermionic or photoemissive processes due to their mobile electrons.
The document summarizes different types of chemical bonds including ionic bonds, covalent bonds, metallic bonds, hydrogen bonds, and Van der Waals interactions. It describes how each type of bond forms and provides examples. Ionic bonds form through electrostatic attraction between oppositely charged ions. Covalent bonds form when atoms share one or more pairs of electrons. Metallic bonds result from delocalized electrons within metal structures. Hydrogen bonds are electrostatic attractions between hydrogen and electronegative atoms. Van der Waals interactions arise from correlations in polarizations between particles.
The atomic mass of an element can vary because the number of neutrons in the nucleus may be variable, even though the number of protons remains the same for a given element. There are four main types of atomic bonding - ionic, covalent, metallic, and van der Waals - which determine key material properties like hardness, melting point, and whether a material is a metal, polymer, or ceramic based on electron configuration and bonding forces between atoms. These bonding types arise from atoms seeking stable electron configurations through gaining, losing, or sharing valence electrons.
Electronic stability control (ESC) uses sensors to detect loss of control and applies brakes to individual wheels to help drivers maintain control and bring the vehicle back on the intended path. ESC was first introduced by BMW in 1980 and later adopted by other manufacturers. It uses wheel speed, vehicle speed, steering wheel angle, and yaw rate sensors along with brake force controllers and a master cylinder to stabilize the vehicle. Studies show ESC can prevent about one-third of fatal accidents.
The document discusses the concept of academic freedom. It defines academic freedom as the freedom of teachers, students, and institutions to pursue knowledge without unreasonable interference. It notes that academic freedom is not unlimited and is still subject to general laws. Teachers have more freedom within their disciplines, and students and teachers gain more freedom as they progress in their education. The document also discusses the 1940 Statement on Principles of Academic Freedom and Tenure by the American Association of University Professors, which aims to protect academic freedom. It notes that while academic freedom is important to allow the open pursuit of knowledge, institutions still have authority over determining educational policies and standards.
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This is a presentation on the time travel.Many of us don't know about time travel, so here you can find the complete information regarding the time travel.
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This is a presentation on the various affects of social media and information about what is meant by social media.I hope that you guys would find this presentation useful.
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This is a presentation on super computers which gives you a better overview on the information of super computers.And i hope that this ppt has been useful for you.
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The following presentation is about the hybrid cars .Here you can get the complete information about the hybrid cars. And i hope that the ppt was useful for you.
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Sexuality - Issues, Attitude and Behaviour - Applied Social Psychology - Psyc...PsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
Authoring a personal GPT for your research and practice: How we created the Q...Leonel Morgado
Thematic analysis in qualitative research is a time-consuming and systematic task, typically done using teams. Team members must ground their activities on common understandings of the major concepts underlying the thematic analysis, and define criteria for its development. However, conceptual misunderstandings, equivocations, and lack of adherence to criteria are challenges to the quality and speed of this process. Given the distributed and uncertain nature of this process, we wondered if the tasks in thematic analysis could be supported by readily available artificial intelligence chatbots. Our early efforts point to potential benefits: not just saving time in the coding process but better adherence to criteria and grounding, by increasing triangulation between humans and artificial intelligence. This tutorial will provide a description and demonstration of the process we followed, as two academic researchers, to develop a custom ChatGPT to assist with qualitative coding in the thematic data analysis process of immersive learning accounts in a survey of the academic literature: QUAL-E Immersive Learning Thematic Analysis Helper. In the hands-on time, participants will try out QUAL-E and develop their ideas for their own qualitative coding ChatGPT. Participants that have the paid ChatGPT Plus subscription can create a draft of their assistants. The organizers will provide course materials and slide deck that participants will be able to utilize to continue development of their custom GPT. The paid subscription to ChatGPT Plus is not required to participate in this workshop, just for trying out personal GPTs during it.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
Current Ms word generated power point presentation covers major details about the micronuclei test. It's significance and assays to conduct it. It is used to detect the micronuclei formation inside the cells of nearly every multicellular organism. It's formation takes place during chromosomal sepration at metaphase.
Immersive Learning That Works: Research Grounding and Paths ForwardLeonel Morgado
We will metaverse into the essence of immersive learning, into its three dimensions and conceptual models. This approach encompasses elements from teaching methodologies to social involvement, through organizational concerns and technologies. Challenging the perception of learning as knowledge transfer, we introduce a 'Uses, Practices & Strategies' model operationalized by the 'Immersive Learning Brain' and ‘Immersion Cube’ frameworks. This approach offers a comprehensive guide through the intricacies of immersive educational experiences and spotlighting research frontiers, along the immersion dimensions of system, narrative, and agency. Our discourse extends to stakeholders beyond the academic sphere, addressing the interests of technologists, instructional designers, and policymakers. We span various contexts, from formal education to organizational transformation to the new horizon of an AI-pervasive society. This keynote aims to unite the iLRN community in a collaborative journey towards a future where immersive learning research and practice coalesce, paving the way for innovative educational research and practice landscapes.
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
(June 12, 2024) Webinar: Development of PET theranostics targeting the molecu...Scintica Instrumentation
Targeting Hsp90 and its pathogen Orthologs with Tethered Inhibitors as a Diagnostic and Therapeutic Strategy for cancer and infectious diseases with Dr. Timothy Haystead.
The cost of acquiring information by natural selectionCarl Bergstrom
This is a short talk that I gave at the Banff International Research Station workshop on Modeling and Theory in Population Biology. The idea is to try to understand how the burden of natural selection relates to the amount of information that selection puts into the genome.
It's based on the first part of this research paper:
The cost of information acquisition by natural selection
Ryan Seamus McGee, Olivia Kosterlitz, Artem Kaznatcheev, Benjamin Kerr, Carl T. Bergstrom
bioRxiv 2022.07.02.498577; doi: https://doi.org/10.1101/2022.07.02.498577
2. HISTORY OF CRYSTAL FIELD THEORY
CFT was developed by physicists Hans Bethe and John Hasbrouk van VECK in 1930’s.
CFT was subsequently combined with Molecular Orbital Theory.
CFT is a bonding model that explains many important properties of transition metal
complexes , including their colours, magnetism ,structures , stability etc.
3. FEATURES OF CRYSTAL FIELD THEORY
CFT assume that bonds between central metal atom or ion and ligands are
purely ionic.
Examples of central metal atoms are Cu ,Mg ,Ca etc.
Ligands are of three types positive, neutral, and negative.
Examples of :-
-ve ligands : F-,Cl-,OH-, CN-
+ve ligands :NO+
Neutral : NH3,H20
4. The arrangement of ligands around the central metal atom or ion is such that
the repulsion between these negative points or dipoles are minimum.
5. The forces between metals and ligands are of two types :-
1. Attraction Force :-
positive charge of the central metal atom and negative charge of ligands.
2. Repulsion Force :-
D-electrons of central metal atom and lone pair electrons of ligands.
D-orbitals of central metal atom are divided into two sets depending on their
orientation.
Non-axial orbitals/ t2g orbitals/ three fold degenerate orbitals :-
dxy, dyz, dxz
Axial orbitals/ eg orbitals/ two fold degenerate orbitals :-
dx2-y2, dz2
14. Uses of Crystal Field Theory :-
1. It can explain high spin and low spin state of coordinate compounds.
2. It can explain magnetic properties of complex compounds.
3. It also explains colour of complex compounds.