This document provides an overview of atomic structure and the development of atomic theory. It discusses the basic composition of atoms, including electrons, protons, and neutrons. It describes Dalton's atomic theory and the key postulates. It also discusses subatomic particles like isotopes, ions, and the discovery of electrons, protons, and neutrons through experiments. The document is divided into sections on the composition of atoms, atomic calculations, isotopes, ions, atomic mass, and the development of atomic theory from Dalton to the discovery of subatomic particles.
The document discusses the structure of atoms. It explains that atoms contain protons, neutrons and electrons. The atomic model has evolved over time from Thomson's "plum pudding" model to Rutherford's discovery of the nucleus at the center of the atom, to Bohr's model of electrons in discrete orbits. It further discusses the distribution of electrons in different shells, an element's valency which is determined by its outer shell electrons, atomic and mass numbers, isotopes and isobars.
Chemical Structure: Structure of Matter. Atoms – the building blocks of matterulcerd
Lecture materials for the Introductory Chemistry course for Forensic Scientists, University of Lincoln, UK. See http://forensicchemistry.lincoln.ac.uk/ for more details.
1. Atoms consist of a positively charged nucleus surrounded by electrons that orbit in defined shells or energy levels.
2. The number of protons in the nucleus defines the atomic number of an element, while the total number of protons and neutrons gives the mass number.
3. Chemical properties are determined by valence electrons in the outer shell. Elements tend to gain or lose electrons to achieve a stable outer shell of 8 electrons.
This document provides a summary of the structure of the atom. It discusses the three main subatomic particles - electrons, protons, and neutrons. It then describes the historical models of the atom including Thomson's plum pudding model, Rutherford's nuclear model, and Bohr's orbital model. Key topics covered include the distribution of electrons in shells, atomic number, mass number, isotopes, isobars, and valency.
J.J. Thomson proposed the plum pudding model where electrons were embedded in a uniform sphere of positive charge, making the atom electrically neutral. However, Rutherford's gold foil experiment found that most alpha particles passed through, but some were deflected at very large angles. This led Rutherford to propose that the positive charge and mass of an atom are concentrated in a very small nucleus, with electrons orbiting the outside. This nuclear model of the atom replaced Thomson's plum pudding model.
This document provides information about atomic structure. It discusses the three main subatomic particles - electrons, protons, and neutrons. It describes the discoveries of these particles by scientists like J.J. Thomson, E. Goldstein, and Chadwick. Models of the atom proposed by scientists like Thomson, Rutherford, and Bohr are explained. The distribution of electrons in different shells is given according to Bohr's model. Information about isotopes, isobars, and valency is also provided.
The document discusses the development of atomic models and the structure of atoms. It describes early models like the plum pudding model and Rutherford's solar system model. Modern atomic structure consists of protons and neutrons in the nucleus and electrons in shells or orbits around the nucleus. The key properties of subatomic particles like protons, neutrons and electrons are given. Proton number is defined as the number of protons in an atom and nucleon number as the sum of protons and neutrons. Examples are provided to show how to determine the number of protons, neutrons and electrons from the periodic table.
The document discusses early theories of atoms and subatomic particles. It describes Dalton's atomic theory and discoveries by Thomson, Rutherford, and Millikan that led to the modern view of the atom. The atom is mostly empty space with a small, dense nucleus containing protons and neutrons. Radioactive decay occurs when unstable nuclei emit alpha, beta, or gamma radiation.
The document discusses the structure of atoms. It explains that atoms contain protons, neutrons and electrons. The atomic model has evolved over time from Thomson's "plum pudding" model to Rutherford's discovery of the nucleus at the center of the atom, to Bohr's model of electrons in discrete orbits. It further discusses the distribution of electrons in different shells, an element's valency which is determined by its outer shell electrons, atomic and mass numbers, isotopes and isobars.
Chemical Structure: Structure of Matter. Atoms – the building blocks of matterulcerd
Lecture materials for the Introductory Chemistry course for Forensic Scientists, University of Lincoln, UK. See http://forensicchemistry.lincoln.ac.uk/ for more details.
1. Atoms consist of a positively charged nucleus surrounded by electrons that orbit in defined shells or energy levels.
2. The number of protons in the nucleus defines the atomic number of an element, while the total number of protons and neutrons gives the mass number.
3. Chemical properties are determined by valence electrons in the outer shell. Elements tend to gain or lose electrons to achieve a stable outer shell of 8 electrons.
This document provides a summary of the structure of the atom. It discusses the three main subatomic particles - electrons, protons, and neutrons. It then describes the historical models of the atom including Thomson's plum pudding model, Rutherford's nuclear model, and Bohr's orbital model. Key topics covered include the distribution of electrons in shells, atomic number, mass number, isotopes, isobars, and valency.
J.J. Thomson proposed the plum pudding model where electrons were embedded in a uniform sphere of positive charge, making the atom electrically neutral. However, Rutherford's gold foil experiment found that most alpha particles passed through, but some were deflected at very large angles. This led Rutherford to propose that the positive charge and mass of an atom are concentrated in a very small nucleus, with electrons orbiting the outside. This nuclear model of the atom replaced Thomson's plum pudding model.
This document provides information about atomic structure. It discusses the three main subatomic particles - electrons, protons, and neutrons. It describes the discoveries of these particles by scientists like J.J. Thomson, E. Goldstein, and Chadwick. Models of the atom proposed by scientists like Thomson, Rutherford, and Bohr are explained. The distribution of electrons in different shells is given according to Bohr's model. Information about isotopes, isobars, and valency is also provided.
The document discusses the development of atomic models and the structure of atoms. It describes early models like the plum pudding model and Rutherford's solar system model. Modern atomic structure consists of protons and neutrons in the nucleus and electrons in shells or orbits around the nucleus. The key properties of subatomic particles like protons, neutrons and electrons are given. Proton number is defined as the number of protons in an atom and nucleon number as the sum of protons and neutrons. Examples are provided to show how to determine the number of protons, neutrons and electrons from the periodic table.
The document discusses early theories of atoms and subatomic particles. It describes Dalton's atomic theory and discoveries by Thomson, Rutherford, and Millikan that led to the modern view of the atom. The atom is mostly empty space with a small, dense nucleus containing protons and neutrons. Radioactive decay occurs when unstable nuclei emit alpha, beta, or gamma radiation.
This document summarizes the history and development of atomic theory from ancient Greek philosophers to modern quantum mechanical models. It begins with Democritus' concept of "atomos" in 500 BC and progresses through John Dalton's atomic theory in 1803, discoveries of the electron by J.J. Thomson and the nuclear model by Ernest Rutherford, to Niels Bohr's model of electron orbits and Erwin Schrodinger's development of quantum mechanics. Key developments include identification of the proton, neutron, and realization that atoms are mostly empty space with electrons in probabilistic orbits around the tiny nucleus.
The document summarizes the structure of an atom in 3 paragraphs:
1) It describes the three main subatomic particles - electrons, protons, and neutrons - and their relative masses and charges.
2) It outlines the historical discoveries of these particles, including Thomson discovering electrons in 1900, discoveries of positively charged particles (protons) in the late 1800s, and Chadwick discovering neutrons in 1932.
3) It discusses several historical models of the atom, including Thomson's "plum pudding" model, Rutherford's discovery of the nucleus from alpha scattering experiments, and Bohr's improvement adding discrete electron orbits that explained atomic stability.
This document provides information about the structure of the atom. It discusses the three main subatomic particles - electrons, protons, and neutrons. It describes the discoveries of these particles by scientists like Thomson, Goldstein, and Chadwick. The document then explains four major atomic models - Thomson's model, Rutherford's model, Bohr's model, and the distribution of electrons in shells. It also discusses concepts like atomic number, mass number, isotopes, isobars, and valency.
objective
theory of atom
dalton`theory
Thomson, s model of atom
atomic number and mass number
isotopes, molecules formula, empirical formula
ions, formula of ionic compound, polyatomic ions, chemical nomenclature
1) Atoms are made up of protons, neutrons, and electrons. Protons and neutrons are in the nucleus, while electrons orbit the nucleus in shells.
2) Isotopes are atoms of the same element that have different numbers of neutrons, giving them different mass numbers but the same chemical properties.
3) Electrons fill the lowest available shell around the nucleus. The arrangement of electrons is shown in an element's electronic structure.
The document discusses the structure of atoms. It explains that atoms are made up of subatomic particles like electrons, protons, and neutrons. J.J. Thomson discovered the electron, while E. Goldstein discovered the positively charged particle, which was later named the proton. Ernest Rutherford's alpha particle scattering experiment provided evidence that the mass and positive charge of an atom are concentrated in a small, dense nucleus at the center. Niels Bohr later proposed that electrons orbit the nucleus in well-defined energy levels or shells. In 1932, James Chadwick discovered the neutron, which has no charge and a mass similar to a proton. The structure of atoms is defined by the number of protons, which determines the element, and
1) Atoms are the smallest particle of an element that retains the properties of that element.
2) Atoms consist of electrons that orbit a nucleus, which contains protons and neutrons.
3) Protons have a positive charge, electrons have a negative charge, and neutrons have no charge. The number of protons defines the element.
4) Atoms are electrically neutral when they contain an equal number of protons and electrons. Ions are formed when atoms gain or lose electrons.
The document discusses the structure of atoms and isotopes. It begins by defining matter and the particle theory of matter. It then explains that atoms are made up of protons, neutrons and electrons. The atomic structure of various elements is discussed through their electron configurations. Isotopes are then introduced as atoms of the same element that have the same number of protons but different numbers of neutrons. Examples of isotopes including hydrogen and oxygen isotopes are provided.
This document summarizes key concepts about atomic structure and the periodic table. It introduces the periodic table and describes the properties and organization of elements in groups and periods. It then discusses atomic structure models including the Thompson, Rutherford, Bohr, and quantum mechanical models. Finally, it covers periodic trends in atomic radius, ionization energy, and electronegativity as well as formation of ions, isotopes, and average atomic mass.
This chapter discusses atomic structure and is divided into four sections. Section 5.1 describes the components of an atom, including protons, neutrons, and electrons, and their relative masses and charges. Section 5.2 defines proton number and nucleon number, and how they relate to the number of protons, neutrons, and electrons in an atom. Section 5.3 explains that isotopes are atoms of the same element with different numbers of neutrons. Section 5.4 discusses how electrons are arranged in shells or energy levels around the atomic nucleus.
There are several misconceptions about the valence shell of the atom. The key questions that arise in the minds of the learners are:
Is valence shell really the outermost shell?
2. Are there only seven shells in an atom?
3. When shells are supposed to be made up of subshells, why can we not represent the subshells in the valence shell structure of the atom?
4. When electrons are said to occur in orbitals, why can we not indicate the orbitals in the valence shell structure?
4. How can we represent the origins for valance band and conduction band in the atomic structure?
5. What are some good metaphors for the core of the atom and the rest of the atom?
Here is a lesson created by Chemistry teachers to address these misconceptions.
This document provides an overview of basic chemistry concepts including:
1) Definitions of key terms like matter, atoms, molecules, elements, compounds, and mixtures.
2) Descriptions of the three states of matter - solids, liquids, and gases - and physical and chemical properties.
3) Explanations of units and measurements in chemistry including the SI system and exponential notation.
4) A brief history of atomic structure theories from Greek philosophers to Rutherford's model of the atom.
This represents two isotopes of carbon:
1. Carbon-12: Has 6 protons and 6 neutrons. Neutral charge.
2. Carbon-13: Has 6 protons and 7 neutrons. Also neutral charge.
Carbon-13 is a stable isotope of carbon. The increased neutron number makes it an isotope. Both have 6 protons so they are the element carbon.
The document provides information about atomic structure including:
- Atoms are made up of protons, neutrons, and electrons.
- Elements are arranged in the periodic table based on their atomic structure.
- The periodic table is organized into periods and groups based on similarities in electrons and properties.
- Electrons fill atomic orbitals according to specific rules, with the first shell holding up to 2 electrons and subsequent shells holding up to 8 electrons each.
Hello everyone, I am Dr. Ujwalkumar Trivedi, Head of Biotechnology Department at Marwadi University Rajkot. I teach Molecular Biology to the students of M.Sc. Microbiology and Biotechnology.
The current presentation is about the historical perspectives of the discovery of atoms and subatomic particles. The later part of the presentation describes various atomic models and the properties of subatomic particles with a description of commonly used terms like molecules, ions and compounds.
this ppt is all about basic working of most basic unit atom. and could enrich your knowledge about atom. and follow me at my instagram
https://www.instagram.com/shantanu_stark/?hl=en
The document discusses the structure and composition of atoms. It can be summarized as follows:
1) Atoms have a small, dense nucleus containing protons and neutrons, surrounded by an electron cloud where electrons are found.
2) The number of protons determines the element, and protons plus neutrons equals the mass number. Electrons equal protons for neutral atoms.
3) Atoms can gain or lose electrons to become ions with a positive or negative charge.
4) Isotopes of the same element have different numbers of neutrons but the same number of protons.
1. The document discusses the progression of atomic theory from ancient Greek philosophers to modern quantum mechanical models. Key contributors and their discoveries are outlined, including Dalton's atomic theory, Thomson's discovery of the electron, and Rutherford's gold foil experiment.
2. Features of the periodic table are explained, including its organization by atomic number and properties that can be predicted from an element's location. Isotopes and how to calculate average atomic mass are also covered.
3. The formation of ions through gaining or losing electrons and predicting ionic charges from the periodic table are summarized. Ionic compounds are defined as electrically neutral combinations of cations and anions.
1) Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons.
2) Electrons are arranged in shells around the nucleus numbered 1, 2, 3, etc. The first shell can hold up to 2 electrons and subsequent shells can hold up to 8 electrons.
3) To find an element's electronic configuration, electrons are filled into the lowest available energy shell first.
Matter is made up of particles, including atoms, molecules, and ions. Atoms are the smallest particles that make up elements. Matter exists in three states - solid, liquid, and gas - depending on how closely or loosely packed the particles are. In solids, particles vibrate in fixed positions; in liquids, they can move around but remain close together; and in gases, particles are far apart and move quickly in random directions. Phase changes between these states, such as melting, boiling, condensing, and sublimating, involve changes to the energy and movement of particles.
This document provides an overview of the textbook "Environmental Soil and Water Chemistry: Principles and Applications" by V.P. Evangelou. The textbook covers principles of water chemistry, solution-mineral chemistry, soil minerals and surface properties, sorption and exchange reactions, redox chemistry and kinetics, soil dynamics related to organic matter and nutrients, colloids and transport processes in soils, salt-affected soils and brackish waters, acid drainage prevention technologies, and water quality and treatment technologies. The textbook is intended to provide students with the fundamental chemical principles needed to understand environmental processes in soil and water systems.
This document summarizes the history and development of atomic theory from ancient Greek philosophers to modern quantum mechanical models. It begins with Democritus' concept of "atomos" in 500 BC and progresses through John Dalton's atomic theory in 1803, discoveries of the electron by J.J. Thomson and the nuclear model by Ernest Rutherford, to Niels Bohr's model of electron orbits and Erwin Schrodinger's development of quantum mechanics. Key developments include identification of the proton, neutron, and realization that atoms are mostly empty space with electrons in probabilistic orbits around the tiny nucleus.
The document summarizes the structure of an atom in 3 paragraphs:
1) It describes the three main subatomic particles - electrons, protons, and neutrons - and their relative masses and charges.
2) It outlines the historical discoveries of these particles, including Thomson discovering electrons in 1900, discoveries of positively charged particles (protons) in the late 1800s, and Chadwick discovering neutrons in 1932.
3) It discusses several historical models of the atom, including Thomson's "plum pudding" model, Rutherford's discovery of the nucleus from alpha scattering experiments, and Bohr's improvement adding discrete electron orbits that explained atomic stability.
This document provides information about the structure of the atom. It discusses the three main subatomic particles - electrons, protons, and neutrons. It describes the discoveries of these particles by scientists like Thomson, Goldstein, and Chadwick. The document then explains four major atomic models - Thomson's model, Rutherford's model, Bohr's model, and the distribution of electrons in shells. It also discusses concepts like atomic number, mass number, isotopes, isobars, and valency.
objective
theory of atom
dalton`theory
Thomson, s model of atom
atomic number and mass number
isotopes, molecules formula, empirical formula
ions, formula of ionic compound, polyatomic ions, chemical nomenclature
1) Atoms are made up of protons, neutrons, and electrons. Protons and neutrons are in the nucleus, while electrons orbit the nucleus in shells.
2) Isotopes are atoms of the same element that have different numbers of neutrons, giving them different mass numbers but the same chemical properties.
3) Electrons fill the lowest available shell around the nucleus. The arrangement of electrons is shown in an element's electronic structure.
The document discusses the structure of atoms. It explains that atoms are made up of subatomic particles like electrons, protons, and neutrons. J.J. Thomson discovered the electron, while E. Goldstein discovered the positively charged particle, which was later named the proton. Ernest Rutherford's alpha particle scattering experiment provided evidence that the mass and positive charge of an atom are concentrated in a small, dense nucleus at the center. Niels Bohr later proposed that electrons orbit the nucleus in well-defined energy levels or shells. In 1932, James Chadwick discovered the neutron, which has no charge and a mass similar to a proton. The structure of atoms is defined by the number of protons, which determines the element, and
1) Atoms are the smallest particle of an element that retains the properties of that element.
2) Atoms consist of electrons that orbit a nucleus, which contains protons and neutrons.
3) Protons have a positive charge, electrons have a negative charge, and neutrons have no charge. The number of protons defines the element.
4) Atoms are electrically neutral when they contain an equal number of protons and electrons. Ions are formed when atoms gain or lose electrons.
The document discusses the structure of atoms and isotopes. It begins by defining matter and the particle theory of matter. It then explains that atoms are made up of protons, neutrons and electrons. The atomic structure of various elements is discussed through their electron configurations. Isotopes are then introduced as atoms of the same element that have the same number of protons but different numbers of neutrons. Examples of isotopes including hydrogen and oxygen isotopes are provided.
This document summarizes key concepts about atomic structure and the periodic table. It introduces the periodic table and describes the properties and organization of elements in groups and periods. It then discusses atomic structure models including the Thompson, Rutherford, Bohr, and quantum mechanical models. Finally, it covers periodic trends in atomic radius, ionization energy, and electronegativity as well as formation of ions, isotopes, and average atomic mass.
This chapter discusses atomic structure and is divided into four sections. Section 5.1 describes the components of an atom, including protons, neutrons, and electrons, and their relative masses and charges. Section 5.2 defines proton number and nucleon number, and how they relate to the number of protons, neutrons, and electrons in an atom. Section 5.3 explains that isotopes are atoms of the same element with different numbers of neutrons. Section 5.4 discusses how electrons are arranged in shells or energy levels around the atomic nucleus.
There are several misconceptions about the valence shell of the atom. The key questions that arise in the minds of the learners are:
Is valence shell really the outermost shell?
2. Are there only seven shells in an atom?
3. When shells are supposed to be made up of subshells, why can we not represent the subshells in the valence shell structure of the atom?
4. When electrons are said to occur in orbitals, why can we not indicate the orbitals in the valence shell structure?
4. How can we represent the origins for valance band and conduction band in the atomic structure?
5. What are some good metaphors for the core of the atom and the rest of the atom?
Here is a lesson created by Chemistry teachers to address these misconceptions.
This document provides an overview of basic chemistry concepts including:
1) Definitions of key terms like matter, atoms, molecules, elements, compounds, and mixtures.
2) Descriptions of the three states of matter - solids, liquids, and gases - and physical and chemical properties.
3) Explanations of units and measurements in chemistry including the SI system and exponential notation.
4) A brief history of atomic structure theories from Greek philosophers to Rutherford's model of the atom.
This represents two isotopes of carbon:
1. Carbon-12: Has 6 protons and 6 neutrons. Neutral charge.
2. Carbon-13: Has 6 protons and 7 neutrons. Also neutral charge.
Carbon-13 is a stable isotope of carbon. The increased neutron number makes it an isotope. Both have 6 protons so they are the element carbon.
The document provides information about atomic structure including:
- Atoms are made up of protons, neutrons, and electrons.
- Elements are arranged in the periodic table based on their atomic structure.
- The periodic table is organized into periods and groups based on similarities in electrons and properties.
- Electrons fill atomic orbitals according to specific rules, with the first shell holding up to 2 electrons and subsequent shells holding up to 8 electrons each.
Hello everyone, I am Dr. Ujwalkumar Trivedi, Head of Biotechnology Department at Marwadi University Rajkot. I teach Molecular Biology to the students of M.Sc. Microbiology and Biotechnology.
The current presentation is about the historical perspectives of the discovery of atoms and subatomic particles. The later part of the presentation describes various atomic models and the properties of subatomic particles with a description of commonly used terms like molecules, ions and compounds.
this ppt is all about basic working of most basic unit atom. and could enrich your knowledge about atom. and follow me at my instagram
https://www.instagram.com/shantanu_stark/?hl=en
The document discusses the structure and composition of atoms. It can be summarized as follows:
1) Atoms have a small, dense nucleus containing protons and neutrons, surrounded by an electron cloud where electrons are found.
2) The number of protons determines the element, and protons plus neutrons equals the mass number. Electrons equal protons for neutral atoms.
3) Atoms can gain or lose electrons to become ions with a positive or negative charge.
4) Isotopes of the same element have different numbers of neutrons but the same number of protons.
1. The document discusses the progression of atomic theory from ancient Greek philosophers to modern quantum mechanical models. Key contributors and their discoveries are outlined, including Dalton's atomic theory, Thomson's discovery of the electron, and Rutherford's gold foil experiment.
2. Features of the periodic table are explained, including its organization by atomic number and properties that can be predicted from an element's location. Isotopes and how to calculate average atomic mass are also covered.
3. The formation of ions through gaining or losing electrons and predicting ionic charges from the periodic table are summarized. Ionic compounds are defined as electrically neutral combinations of cations and anions.
1) Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons.
2) Electrons are arranged in shells around the nucleus numbered 1, 2, 3, etc. The first shell can hold up to 2 electrons and subsequent shells can hold up to 8 electrons.
3) To find an element's electronic configuration, electrons are filled into the lowest available energy shell first.
Matter is made up of particles, including atoms, molecules, and ions. Atoms are the smallest particles that make up elements. Matter exists in three states - solid, liquid, and gas - depending on how closely or loosely packed the particles are. In solids, particles vibrate in fixed positions; in liquids, they can move around but remain close together; and in gases, particles are far apart and move quickly in random directions. Phase changes between these states, such as melting, boiling, condensing, and sublimating, involve changes to the energy and movement of particles.
This document provides an overview of the textbook "Environmental Soil and Water Chemistry: Principles and Applications" by V.P. Evangelou. The textbook covers principles of water chemistry, solution-mineral chemistry, soil minerals and surface properties, sorption and exchange reactions, redox chemistry and kinetics, soil dynamics related to organic matter and nutrients, colloids and transport processes in soils, salt-affected soils and brackish waters, acid drainage prevention technologies, and water quality and treatment technologies. The textbook is intended to provide students with the fundamental chemical principles needed to understand environmental processes in soil and water systems.
This document provides information about research projects available at a research lab in Chennai, India. It lists contact details including email and phone number, and specifies they are looking for final year undergraduate and graduate students in electrical engineering fields to work on projects. Students will be able to assemble hardware in the lab and receive guidance from experts.
This document discusses photos taken at the Pullman Hotel Central Park Jakarta using a Nikon CoolPix 12mp camera. The photos show the blue-colored Preps Kitchen, food preparation and display areas, steam kitchen, and meals being enjoyed. The document thanks the Pullman Hotel Central Park Jakarta for hosting the photo shoot.
Scada for power system automation - Power Systems final year ProjectSenthil Kumar
Power Electronics Titles
ME (Power Electronics and Drives)
Due importance is accorded to both subjects and dissertation work. Each of these Projects are handled by chosen, experienced staff, and is complemented by senior practicing experts from reputed industry. The dissertation work is supervised meticulously by our specialized faculty.
Phase 1 and Phase II
Number of Projects per academic year - 50 Numbers Including Funded Projects . Selection Process - First come First serve Basis.
Three phase inverter and converters
Buck Boost Converter using 89s51
Matrix Converter Using Micro Controllers
Inverter and converter topologies
Fuzzy based control of Electric Drives.
Optimal design of Electrical Machines
BLDC and SR motor Drives
This document lists 161 potential project titles for PC-based projects. The projects cover a wide range of topics including robotics, biomedical devices, instrumentation, power systems, electronics, and more. Many involve interfacing a PC to other devices using technologies like serial communication, wireless transmission, and fiber optic cables. The document also provides contact information for an organization called Expert Systems and Solutions that may provide assistance or tutoring on the listed projects.
The document provides an overview of the Indian steel industry. It discusses the industry's vision, mission, major players, growth over the years through acquisitions and investments, impact of macroeconomic variables like GDP, inflation, and dumping. Key points include that India is the 5th largest steel producer globally and is expected to become 2nd largest by 2015-16. Economic growth and infrastructure development is driving steel demand growth. However, high inflation is negatively impacting consumer industries and slowing steel demand.
This document provides an overview of search engine optimization (SEO) and why websites need to be optimized. It discusses how search engines like Google work and the importance of keyword research. The document outlines best practices for on-page SEO like including target keywords in headings and body text. It also discusses off-page SEO factors like building relevant links. Additionally, the document covers Google algorithm updates like Panda and Penguin, and emphasizes that quality, relevant content is key to success with SEO.
This document lists 475 electronics projects from a company called Expert Systems and Solutions located in Chennai, Tamil Nadu, India. The projects range from basic electronics kits and testers to more advanced systems like security systems, wireless transmitters/receivers, motor controllers, and data loggers. The company's website is provided for more details on their products and services.
EXPERT SYSTEMS AND SOLUTIONS
Project Center For Research in Power Electronics and Power Systems
IEEE 2010 , IEEE 2011 BASED PROJECTS FOR FINAL YEAR STUDENTS OF B.E
Email: expertsyssol@gmail.com,
Cell: +919952749533, +918608603634
www.researchprojects.info
OMR, CHENNAI
IEEE based Projects For
Final year students of B.E in
EEE, ECE, EIE,CSE
M.E (Power Systems)
M.E (Applied Electronics)
M.E (Power Electronics)
Ph.D Electrical and Electronics.
Training
Students can assemble their hardware in our Research labs. Experts will be guiding the projects.
EXPERT GUIDANCE IN POWER SYSTEMS POWER ELECTRONICS
We provide guidance and codes for the for the following power systems areas.
1. Deregulated Systems,
2. Wind power Generation and Grid connection
3. Unit commitment
4. Economic Dispatch using AI methods
5. Voltage stability
6. FLC Control
7. Transformer Fault Identifications
8. SCADA - Power system Automation
we provide guidance and codes for the for the following power Electronics areas.
1. Three phase inverter and converters
2. Buck Boost Converter
3. Matrix Converter
4. Inverter and converter topologies
5. Fuzzy based control of Electric Drives.
6. Optimal design of Electrical Machines
7. BLDC and SR motor Drives
This document contains a presentation on mobile application performance optimization. It discusses how things like inefficient data connections, high latency, repetitive downloads, unnecessary network requests, large images, and slow loading times can negatively impact the user experience and business metrics. The presentation provides examples of performance issues found in various apps and recommends solutions like caching content, only making necessary requests, compressing data, and using activity detection to optimize network usage. The overarching message is that application performance is critical for user retention, engagement, and business success.
This document provides a list of over 110 potential robotics project titles. It is from a company called Expert Systems and Solutions located in Chennai, Tamil Nadu, India that provides engineering services including robotics projects, online coaching, and jobs. The list covers a wide range of robotics projects involving path finding, picking and placing objects, spraying, welding, cleaning, sensing, and more.
Leigh Ellen Lillis is seeking a position as a Medical Technical Writer and Editor. She has over 20 years of experience in technical writing and editing. She created documentation such as policies, procedures, workflows and training materials. Most recently, she has worked as a contract technical writer for various companies in healthcare and other industries. She has a certificate in Medical Writing and Editing from University of Chicago and is proficient in interviewing experts and developing technical documentation.
The new edition of the Skoltech faculty prospectus is now available online.
You are welcome to read through this brochure and learn about members of our faculty and their various research projects: bio-medicinal therapies, computer vision, hydrocarbon recovery and renewable energy, quantum physics and string theory, satellite systems and space exploration, composite materials and manufacturing, innovation and product realization, and many more.
The prospectus outlines collaboration with leading international partners (such as MIT) and Russian institutions, current developments and past milestones. It also provides a look at Skoltech’s vision, as well as at our concrete development plans.
Feel free to share this document, using the social media buttons or provided link. We hope you find the reading as informative and inspiring as our team did.
* The Skolkovo Institute of Science and Technology (Skoltech) is a private graduate research university in Skolkovo, Russia, a suburb of Moscow. Established in 2011 in collaboration with MIT, Skoltech educates global leaders in innovation, advance scientific knowledge, and foster new technologies to address critical issues facing Russia and the world. Applying international research and educational models, the university integrates the best Russian scientific traditions with twenty-first century entrepreneurship and innovation.
The document summarizes key concepts about atomic structure and the periodic table. It discusses the composition of atoms including electrons, protons, and neutrons. It describes Dalton's atomic theory and the discoveries of subatomic particles. The periodic table is introduced, including its organization by family and period. The periodic law is explained. Electron configuration and arrangements are covered, including energy levels, subshells, orbitals, and electron spin.
This document provides information about atomic structure and the periodic table. It includes:
1) An overview of the three basic subatomic particles - protons, neutrons, and electrons - that make up all atoms.
2) Details about the characteristics of protons, neutrons, and electrons, including their location, charge, and relative mass.
3) A description of isotopes and the three natural isotopes of hydrogen.
4) Homework assigned which includes completing power notes on atomic structure.
All you need_to_know_about_additional_science[1]lucywalshaw
Structures and bonding, properties of materials, quantitative chemistry and rates of reaction are discussed. Key topics covered include atomic structure, ionic and covalent bonding, properties of materials like conductivity and melting points, amounts of substances and moles, balancing chemical equations, factors that affect rates of reaction like temperature, concentration and surface area. The document provides an overview of content to be covered in additional science chapters on these core chemistry concepts.
All you need_to_know_about_additional_science[2]mcconvillezoe
This document provides an overview of additional science topics including atomic structure, bonding, properties of materials, quantitative chemistry concepts like moles and reacting masses, rates of reaction influenced by factors like concentration and catalysts, energy changes in reactions, electrolysis and information about acids, bases, salts and their reactions. It includes chapter outlines, explanations of concepts, diagrams and examples to illustrate essential ideas in chemistry.
This document is a chapter about atomic structure and the periodic table. It covers subatomic particles like electrons, protons, and neutrons. It defines key terms like atomic number, mass number, and isotopes. It introduces the periodic table and explains how elements are arranged based on recurring trends in chemical properties, with similar elements found in the same groups. Metals are defined as lustrous, conductive, and malleable elements, while nonmetals lack those properties.
This document provides an overview of basic chemistry concepts. It explains that all matter is made up of atoms, and atoms can combine to form either elements or compounds. The structure of the atom is described, including subatomic particles like protons, neutrons, and electrons. Electron configuration and chemical bonding via ionic and covalent bonds are also summarized. Key terms like isotopes, ions, the periodic table, and electronegativity are defined.
1. Chemistry is central to understanding biological processes as we are composed of chemicals and chemical reactions drive life.
2. At the most basic level, all matter is composed of atoms that can bond through ionic or covalent bonds to form molecules and compounds.
3. Organic compounds that contain carbon, such as carbohydrates, lipids, proteins, and nucleic acids, are unique to living systems and are built through polymerization reactions involving monomers.
The document discusses atoms and the periodic table. It describes how atoms are made up of protons, neutrons, and electrons. Elements are organized on the periodic table based on their atomic structure. Each element has a unique atomic symbol and atomic mass. Isotopes are variants of the same element that have different numbers of neutrons. Ions are formed when atoms gain or lose electrons, acquiring an electrical charge.
The document provides information about atoms and the structure of matter in three sections:
1. Atoms are the building blocks of matter and consist of protons, neutrons, and electrons. The arrangement of atoms determines the properties of different types of matter.
2. Atoms can combine to form compounds and molecules through chemical bonds. Compounds have unique properties that differ from their constituent elements.
3. Matter exists in four states - solid, liquid, gas, and plasma. The state depends on how tightly or freely the atoms and molecules are able to move. Solids have a fixed structure while gases spread freely.
Dr. Kamal K. Ali's lecture discusses the structure of atoms and radioactivity. It covers topics like the atom structure, isotopes, radioactive decay mechanisms, and types of radiation. It also explains techniques used to measure isotopes like mass spectrometry. Mass spectrometry works by ionizing atoms, accelerating the ions, and separating them in a magnetic field based on their mass-to-charge ratio. This allows determining the relative abundances of isotopes in a sample.
The document discusses the atomic theory of matter and the development of atomic structure models. It describes John Dalton's atomic theory which stated that elements are composed of atoms that are unique and atoms are neither created nor destroyed in chemical reactions. The discovery of the electron by J.J. Thompson and experiments by Robert Millikan and Ernest Rutherford helped develop the modern atomic structure model of a small, dense nucleus surrounded by electrons. The document also discusses isotopes, atomic numbers, mass numbers, and how the periodic table is arranged based on atomic structure.
This document provides information about atomic structure and the history of atomic theory. It discusses early Greek philosophers' ideas of atoms, followed by key scientists and their experiments and models that advanced our understanding:
1) Dalton established the first modern atomic theory, proposing that all matter is made of tiny indivisible particles called atoms.
2) Rutherford's gold foil experiment showed that the mass of an atom is concentrated in a small, positively charged nucleus at the center.
3) Bohr incorporated Rutherford's findings into his planetary model of electrons orbiting the nucleus.
4) Schrödinger introduced the wave mechanical model where electrons vibrate around the nucleus rather than following precise orbits.
The document summarizes key developments in the atomic theory of matter:
1) Early Greek philosophers like Democritus proposed ideas of atoms as indivisible particles that make up all matter.
2) Scientists like Lavoisier, Dalton, and Thomson contributed experimental evidence and early atomic models, including Dalton's first modern atomic theory stating atoms are indestructible particles that combine in specific ratios.
3) Rutherford's gold foil experiment provided evidence that atoms are mostly empty space with a small, dense positively charged nucleus at the center, overturning the plum pudding model.
This document provides an overview of the history and development of atomic structure theory. It discusses early Greek philosophers like Democritus who proposed that all matter is made of tiny indivisible particles called atoms. It then outlines key discoveries and models proposed by scientists like Lavoisier, Dalton, Thomson, Rutherford, Bohr, Schrodinger that helped develop our modern understanding of atomic structure. The basic structure of an atom is described including the subatomic particles (protons, neutrons, electrons), their properties, and location within the atom. The nucleus is identified as containing most of the atom's mass.
This document provides an overview of the history and development of atomic structure theories from ancient Greece to modern times. It discusses key contributors including:
- Democritus (400 BC) who first proposed the idea of atoms as tiny indivisible particles.
- Dalton (1817-1844) who developed the first modern atomic theory stating that all matter is composed of atoms that combine in specific ratios.
- Rutherford (1898) whose gold foil experiment showed that atoms are mostly empty space with a small, dense positively charged nucleus at the center.
- Bohr (1922) who proposed the planetary model of electrons orbiting the nucleus like planets around the sun.
- Schröding
This document provides an overview of the history and development of atomic structure and the periodic table. It discusses key contributors such as Democritus, Dalton, Thomson, Rutherford, Bohr, and Schrodinger and their models of the atom. The basic atomic structure consists of protons, neutrons, and electrons. The nucleus contains protons and neutrons and holds most of the atom's mass, while electrons orbit outside the nucleus. Isotopes are atoms of the same element with different numbers of neutrons. The periodic table organizes elements based on their atomic structure.
This document discusses the structure of atoms and the periodic table. It describes atoms as being made up of protons, neutrons, and electrons. Elements are organized on the periodic table according to their atomic structure. The periodic table lists the atomic number and average atomic mass of each element. Isotopes are variants of elements that have different numbers of neutrons but the same number of protons. Ions are formed when atoms gain or lose electrons, becoming positively or negatively charged.
The document discusses the atomic model and structure of atoms. It states that atoms are comprised of protons, neutrons, and electrons, with protons and neutrons located in the central nucleus and electrons surrounding it in empty space. Protons are positively charged, electrons are negatively charged, and neutrons have no charge. The sizes of atoms and their components are described, with the nucleus being very small compared to the mostly empty space occupied by electrons. A brief history of atomic models is also provided.
This document provides an overview of key concepts from Chapter 2 of Campbell Biology about the chemical context of life. It discusses the basic components of atoms and molecules, including elements, compounds, ions, and the different types of chemical bonds. It also summarizes the structure of atoms and how this relates to an element's properties. Additionally, it outlines important chemical reactions like photosynthesis and explains concepts like chemical equilibrium. The overall summary is that chemistry provides the building blocks and forces that shape biological molecules and drive metabolic reactions.
This document provides a review of atomic structure concepts and homework assignments. It reviews key terms like isotopes, ions, subatomic particles, and periodic table organization. Students are asked review questions about protons, neutrons, electrons, atomic mass and charge. The document provides explanations that the number of protons identifies the element, and that atoms are neutral because they have the same number of protons and electrons. It assigns reading from notes on atomic structure and applications to color and complete exercises in the periodic table.
This document discusses the structure, nomenclature, properties, and synthesis of hydrocarbons. It defines hydrocarbons as compounds composed of only carbon and hydrogen. Alkanes are saturated hydrocarbons with an open chain structure. Alkanes have the general formula CnH2n+2. Constitutional isomers have the same molecular formula but different connectivity of atoms. Higher molecular weight alkanes are liquids or solids at room temperature due to dispersion forces between molecules. Alkanes are important energy sources due to their high heat of combustion when oxidized. Natural gas, petroleum, and coal are major natural sources of alkanes.
The document discusses radioactivity and nuclear medicine, including defining nuclear symbols, describing different types of radiation like alpha and beta particles and gamma rays, properties of radioisotopes such as half-life, and medical applications of radioactivity including using isotopes for cancer therapy and nuclear medicine procedures like tracer studies.
This document provides an overview of acids and bases including:
1) It describes the Arrhenius and Brønsted-Lowry theories of acids and bases, defining acids as proton donors and bases as proton acceptors.
2) It discusses strong vs. weak acids and bases based on their degree of dissociation in water, and introduces conjugate acid-base pairs.
3) It explains that water can act as both an acid and base, and discusses the autoionization of water and the definition of pH in terms of the hydronium ion concentration.
Spontaneous processes occur naturally without an external stimulus, while nonspontaneous processes require something to be done to occur. Whether a reaction is spontaneous can be determined using thermodynamics by calculating the enthalpy and entropy. Energy exists in various forms including thermal, electrical, chemical, and kinetic, and it can be transferred or changed between objects and forms. During chemical reactions, energy is either absorbed or released as bonds break and form.
This document provides an overview of acids and bases including:
1) It describes the Arrhenius and Brønsted-Lowry theories of acids and bases, defining acids as proton donors and bases as proton acceptors.
2) It discusses strong vs. weak acids and bases based on their degree of dissociation in water, and introduces conjugate acid-base pairs.
3) It explains that water can act as both an acid and base, and discusses the autoionization of water and the definition of pH in terms of the hydronium ion concentration.
Spontaneous processes occur naturally without an external stimulus, while nonspontaneous processes require something to be done to occur. Whether a reaction is spontaneous can be determined using thermodynamics by calculating the enthalpy and entropy. Energy exists in various forms including thermal, electrical, chemical, and kinetic, and it can be transferred or changed between objects and forms. During chemical reactions, energy is either absorbed or released as bonds break and form.
This chapter discusses the three states of matter - gases, liquids, and solids. It focuses on the differences in their physical properties. The key gas laws - Boyle's law, Charles's law, and the combined gas law - are introduced. Boyle's law relates the inverse relationship between pressure and volume of a gas at constant temperature. Charles's law describes how the volume of a gas increases directly with temperature at constant pressure. Examples are provided to demonstrate how to apply these gas laws to calculate changes in volume or pressure of a gas under different conditions.
1) The document provides an overview of key concepts in chemistry including the mole concept, chemical formulas and equations, and different types of chemical reactions.
2) It explains that the mole is a unit used to measure amounts of substances and is equal to 6.022x1023 particles. Molar mass refers to the mass of one mole of a substance.
3) Chemical equations are used to represent chemical reactions and must satisfy the law of conservation of mass by being balanced with the same number and type of atoms on each side of the reaction arrow.
This document provides an overview of chemical bonding and the properties of ionic and covalent compounds. It discusses the following key points:
1. Chemical bonds form due to the attraction between atoms and involve the transfer or sharing of valence electrons. Ionic bonds form through electron transfer between metals and nonmetals, while covalent bonds involve electron sharing.
2. Lewis symbols represent atoms and their valence electrons and are used to predict bonding patterns. Electronegativity determines bond polarity.
3. Ionic compounds have high melting and boiling points due to strong electrostatic attractions in the crystal lattice. Covalent compounds can be solids, liquids or gases.
This document provides an overview of key concepts in chemistry, including:
1. Chemistry is the study of matter, its properties, and the changes it undergoes. The scientific method is used to systematically study matter through observation, questioning, experimentation and summarization.
2. Matter can exist in three physical states - solid, liquid, and gas. It also has physical and chemical properties and can undergo physical or chemical changes.
3. The metric system is the standard system of measurement in chemistry. It relates units decimally and is easier for conversion than the English system. Careful measurement and use of appropriate units is important in chemistry.
The document summarizes key concepts about solutions from chapter 6, including:
1) It defines solutions, solutes, solvents, and aqueous solutions.
2) It describes general properties of solutions like transparency, electrolytes vs nonelectrolytes, and how volumes are non-additive.
3) It discusses concentration units like molarity, calculates concentrations from masses and volumes, and explains dilution.
4) It covers colligative properties like vapor pressure lowering, boiling point elevation, freezing point depression, and osmotic pressure that depend on solute concentration.
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This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
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2. 2.1 Composition of the Atom
• Atom - the basic structural unit of an
element
• The smallest unit of an element that
retains the chemical properties of
that element
3. 2.1 Composition of the Atom Electrons, Protons, and Neutrons
• Atoms consist of three primary particles
• electrons
• protons
• neutrons
• Nucleus - small, dense, positively
charged region in the center of the atom
- protons - positively charged particles
- neutrons - uncharged particles
4. 2.1 Composition of the Atom Characteristics of Atomic
Particles
• Electrons are negatively charged particles
located outside of the nucleus of an atom
• Protons and electrons have charges that
are equal in magnitude but opposite in sign
• A neutral atom that has no electrical
charge has the same number of protons
and electrons
• Electrons move very rapidly in a relatively
large volume of space while the nucleus is
small and dense
5. 2.1 Composition of the Atom Symbolic Representation of
an Element
Charge of
particle
Mass
A C
Z X
Atomic Symbol of
number the atom
• Atomic number (Z) - the number of
protons in the atom
• Mass number (A) - sum of the number of
protons and neutrons
6. 2.1 Composition of the Atom
Atomic Calculations
number of protons + number of neutrons = mass number
number of neutrons = mass number - number of protons
number of protons = number of electrons IF positive and
negative charges cancel, the atom charge = 0
8. 2.1 Composition of the Atom
Atomic Composition Calculations
Calculate the number of protons, neutrons,
and electrons in each of the following:
11
5 B
55
26 Fe
9. 2.1 Composition of the Atom Isotopes
• Isotopes - atoms of the same element
having different masses
– contain same number of protons 4
– contain different numbers of neutrons
Isotopes of Hydrogen
Hydrogen Deuterium Tritium
(Hydrogen - 1) (Hydrogen - 2) (Hydrogen - 3)
10. 2.1 Composition of the Atom
Isotopic Calculations
• Isotopes of the same element have identical
chemical properties
• Some isotopes are radioactive
• Find chlorine on the periodic table
• What is the atomic number of chlorine?
17
• What is the mass given?
35.45
• This is not the mass number of an isotope
11. 2.1 Composition of the Atom Atomic Mass
• What is this number: 35.34?
• The atomic mass - the weighted average of
the masses of all the isotopes that make up
chlorine
• Chlorine consists of chlorine-35 and
chlorine-37 in a 3:1 ratio
• Weighted average is an average corrected
by the relative amounts of each isotope
present in nature
12. 2.1 Composition of the Atom
Atomic Mass Calculation
Calculate the atomic mass of naturally
occurring chlorine if 75.77% of chlorine
atoms are chlorine-35 and 24.23% of
chlorine atoms are chlorine-37
Step 1: convert the percentage to a decimal
fraction:
0.7577 chlorine-35
0.2423 chlorine-37
13. 2.1 Composition of the Atom
Step 2: multiply the decimal fraction by the
mass of that isotope to obtain the isotope
contribution to the atomic mass:
For chlorine-35:
0.7577 x 35.00 amu = 26.52 amu
For chlorine-37
0.2423 x 37.00 amu = 8.965 amu
Step 3: sum these partial weights to get the
weighted average atomic mass of chlorine:
26.52 amu + 8.965 amu = 35.49 amu
14. 2.1 Composition of the Atom
Atomic Mass Determination
• Nitrogen consists of two naturally occurring
isotopes
– 99.63% nitrogen-14 with a mass of 14.003 amu
– 0.37% nitrogen-15 with a mass of 15.000 amu
• What is the atomic mass of nitrogen?
15. 2.1 Composition of the Atom
Ions and Charges
• Ions - electrically charged particles that
result from a gain or loss of one or more
electrons by the parent atom
• Cation - positively charged
– results from the loss of electrons
– 23Na 23Na+ + 1e-
• Anion - negatively charged
– results from the gain of electrons
– 19F + 1e- 19F-
16. 2.1 Composition of the Atom Calculating Subatomic Particles
in Ions
• How many protons, neutrons, and electrons
are in the following ions?
39 +
19 K
32 2-
16 S
24 2+
12 Mg
17. 2.2 Development of Atomic
Theory
• Dalton’s Atomic Theory - the first
experimentally based theory of atomic
structure of the atom
18. Postulates of Dalton’s Atomic Theory
2.2 Development of
1. All matter consists of tiny particles
Atomic Theory
called atoms
2. An atom cannot be created, divided,
destroyed, or converted to any other
type of atom
3. Atoms of a particular element have
identical properties
19. 2.2 Development of
4. Atoms of different elements have
different properties
Atomic Theory
5. Atoms of different elements
combine in simple whole-number
ratios to produce compounds (stable
aggregates of atoms)
6. Chemical change involves joining,
separating, or rearranging atoms
Postulates 1, 4, 5, and 6 are still regarded
as true.
20. Subatomic Particles:
Electrons, Protons, and Neutrons
2.2 Development of
• Electrons were the first subatomic
Atomic Theory
particles to be discovered using the
cathode ray tube.
Indicated that the
particles were
negatively charged.
21. Evidence for Protons and
2.2 Development of
Neutrons
Atomic Theory
• Protons were the next particle to be discovered,
by Goldstein
– Protons have the same size charge but opposite in sign
– A proton is 1,837 times as heavy as an electron
• Neutrons
– Postulated to exist in 1920’s but not demonstrated to
exist until 1932
– Almost the same mass as the proton
22. 2.4 The Periodic Law and the
Periodic Table
• Dmitri Mendeleev and Lothar Meyer - two
scientists working independently developed
the precursor to our modern periodic table
• They noticed that as you list elements in
order of atomic mass, there is a distinct
regular variation of their properties
• Periodic law - the physical and chemical
properties of the elements are periodic
functions of their atomic numbers
23. 2.4 The Periodic Law
and the Periodic Table
Classification of the Elements
24. 2.4 The Periodic Law
and the Periodic Table
Important Biological Elements
25. Parts of the Periodic Table
and the Periodic Table
2.4 The Periodic Law
• Period - a horizontal row of elements in
the periodic table. They contain 2, 8, 8,
18, 18, and 32 elements
• Group - also called families, and are
columns of elements in the periodic table.
• Elements in a particular group or family
share many similarities, as in a human
family.
26. Families of the Periodic Table
and the Periodic Table
2.4 The Periodic Law
• Representative elements - Group A
elements
• Transition elements - Group B
elements
• Alkali metals - Group IA
• Alkaline earth metals - group IIA
• Halogens - group VIIA
• Noble gases - group VIIIA
27. Category Classification of
and the Periodic Table Elements
2.4 The Periodic Law
• Metals - elements that tend to lose
electrons during chemical change,
forming positive ions
• Nonmetals - a substance whose atoms
tend to gain electrons during chemical
change, forming negative ions
• Metalloids - have properties intermediate
between metals and nonmetals
28. Classification of Elements
and the Periodic Table Metals
2.4 The Periodic Law
• Metals:
– A substance whose atoms tend to lose
electrons during chemical change
– Elements found primarily in the left 2/3 of
the periodic table
• Properties:
– High thermal and electrical conductivities
– High malleability and ductility
– Metallic luster
– Solid at room temperature
29. Classification of Elements
and the Periodic Table Nonmetals
2.4 The Periodic Law
• Nonmetals:
– A substance whose atoms may gain
electrons, forming negative ions
– Elements found in the right 1/3 of the
periodic table
• Properties:
– Brittle
– Powdery solids or gases
– Opposite of metal properties
30. Classification of Elements
and the Periodic Table Metalloids
2.4 The Periodic Law
• Metalloids:
– Elements that form a narrow diagonal band
in the periodic table between metals and
nonmetals
• Properties are somewhat between those
of metals and nonmetals
• Also called semimetals
31. Atomic Number and Atomic Mass
and the Periodic Table
2.4 The Periodic Law
• Atomic Number:
– The number of protons in the nucleus of
an atom of an element
– Nuclear charge or positive charge from
the nucleus
• Most periodic tables give the element
symbol, atomic number, and atomic
mass
32. Element Information in the
and the Periodic Table Periodic Table
2.4 The Periodic Law
20 atomic number
Ca symbol
Calcium name
40.08 atomic mass
33. Using the Periodic Table
and the Periodic Table
2.4 The Periodic Law
• Identify the group and period to
which each of the following belongs:
a. P
b. Cr
c. Element 30
• How many elements are found in
period 6?
• How many elements are in group
VA?
34. 2.5 Electron Arrangement and
the Periodic Table
• The electron arrangement is the primary
factor in understanding how atoms join
together to form compounds
• Electron configuration - describes the
arrangement of electrons in atoms
• Valence electrons - outermost electrons
– The electrons involved in chemical bonding
35. 2.5 Electron Arrangement
and the Periodic Table Valence Electrons
• The number of valence electrons is the
group number for the representative
elements
• The period number gives the energy
level (n) of the valence shell for all
elements
36. 2.5 Electron Arrangement Valence Electrons and Energy
and the Periodic Table Level
• How many valence electrons does Fluorine
have?
– 7 valence electrons
• What is the energy level of these electrons?
– Energy level is n = 2
38. 2.5 Electron Arrangement Valence Electrons - Detail
and the Periodic Table • What is the total number of electrons in
fluorine?
– Atomic number = 9
– 9 protons and 9 electrons
• 7 electrons in the valence shell, (n = 2 energy level),
so where are the other two electrons?
– In n = 1 energy level
– Level n = 1 holds only two electrons
39. Determining Electron Arrangement
2.5 Electron Arrangement
and the Periodic Table List the total number of electrons, total number of
valence electrons, and energy level of the valence
electrons for silicon.
1. Find silicon in the periodic table
• Group IVA
• Period 3
• Atomic number = 14
1. Atomic number = number of electrons
in an atom
• Silicon has 14 electrons
40. Determining Electron Arrangement #2
2.5 Electron Arrangement
and the Periodic Table List the total number of electrons, total number of
valence electrons, and energy level of the valence
electrons for silicon.
3. As silicon is in Group IV, only 4 of its 14
electrons are valence electrons
• Group IVA = number of valence electrons
3. Energy levels:
• n = 1 holds 2 electrons
• n = 2 holds 8 electrons (total of 10)
• n = 3 holds remaining 4 electrons (total = 14)
41. Determining Electron Arrangement
2.5 Electron Arrangement
and the Periodic Table Practice
List the total number of electrons, total
number of valence electrons, and energy
level of the valence electrons for:
• Na
• Mg
• S
• Cl
• Ar
42. 2.5 Electron Arrangement
Energy Levels and Subshells
and the Periodic Table
PRINCIPAL ENERGY LEVELS
• n = 1, 2, 3, …
• The larger the value of n, the higher the energy
level and the farther away from the nucleus the
electrons are
• The number of sublevels in a principal energy
level is equal to n
– in n = 1, there is one sublevel
– in n = 2, there are two sublevels
43. 2.5 Electron Arrangement Principal Energy Levels
and the Periodic Table • The electron capacity of a principal
energy level (or total electrons it can hold) is
2(n)2
– n = 1 can hold 2(1)2 = 2 electrons
– n = 2 can hold 2(2)2 = 8 electrons
• How many electrons can be in the n = 3
level?
– 2(3)2 = 18
• Compare the formula with periodic table…..
44. n = 1, 2(1)2 = 2
n = 2, 2(2)2 = 8
n = 3, 2(3)2 = 18
n = 4, 2(4)2 = 32
45. 2.5 Electron Arrangement Sublevels
and the Periodic Table • Sublevel: a set of energy-equal orbitals
within a principal energy level
• Subshells increase in energy:
s<p<d<f
• Electrons in 3d subshell have more energy
than electrons in the 3p subshell
• Specify both the principal energy level and a
subshell when describing the location of an
electron
46. 2.5 Electron Arrangement
Sublevels in Each Energy Level
and the Periodic Table
Principle energy Possible
level (n) subshells
1 1s
2 2s, 2p
3 3s, 3p, 3d
4 4s, 4p, 4d, 4f
47. 2.5 Electron Arrangement Orbitals
and the Periodic Table
• Orbital - a specific region of a sublevel
containing a maximum of two electrons
• Orbitals are named by their sublevel and
principal energy level
– 1s, 2s, 3s, 2p, etc.
• Each type of orbital has a characteristic
shape
– s is spherically symmetrical
– p has a shape much like a dumbbell
48. 2.5 Electron Arrangement
Orbital Shapes
and the Periodic Table
• s is spherically
symmetrical
• Each p has a shape much like a dumbbell,
differing in the direction extending into space
49. Number of
2.5 Electron Arrangement Subshell
orbitals
and the Periodic Table
s 1
p 3
d 5
f 7
•How many electrons can be in the 4d
•10
50. 2.5 Electron Arrangement
Quantum Mechanical Model
and the Periodic Table Shell 4
• Each orbital within a
sublevel contains a 4f •• •• •• •• •• •• ••
maximum of 2
Increasing Energy
electrons
4d •• •• •• •• ••
• Energy increases as n,
shell number Sublevel
increases, but ALSO 4p •• •• ••
increases as you move
from s to p to d to f Orbital
sublevels 4s ••
Electron
51. 2.5 Electron Arrangement Electron Spin
and the Periodic Table • Electron configuration - the
arrangement of electrons in atomic
orbitals
• Aufbau principle - or building up
principle helps determine the electron
configuration
– Electrons fill the lowest-energy orbital that
is available first
– Remember s<p<d<f in energy
– When the orbital contains two electrons,
the electrons are said to be paired
53. 2.5 Electron Arrangement Rules for Writing Electron
and the Periodic Table Configurations
• Obtain the total number of electrons in the atom
from the atomic number
• Electrons in atoms occupy the lowest energy
orbitals that are available – 1s first
• Each principal energy level, n contains only n
sublevels
• Each sublevel is composed of orbitals
• No more than 2 electrons in any orbital
• Maximum number of electrons in any principal
energy level is 2(n)2
54. 2.5 Electron Arrangement Electron Distribution
and the Periodic Table • This table lists the number of electrons in each
shell for the first 20 elements
• Note that 3rd shell stops filling at 8 electrons even though
it could hold more
56. Writing Electron Configurations
2.5 Electron Arrangement
and the Periodic Table
• H • Li
– Hydrogen has – Lithium has 3
only 1 electron electrons
– It is in the – First two have
lowest energy configuration
level & lowest of Helium – 1s2
orbital – 3rd is in the
– Indicate orbital of
number of lowest energy
electrons with a in n=2
superscript – 1s2 2s1
– 1s1
57. 2.5 Electron Arrangement
Electron Configuration Examples
and the Periodic Table
• Give the complete electron
configuration of each element
– Be
–N
– Na
– Cl
– Ag
58. 2.5 Electron Arrangement
and the Periodic Table The Shell Model and Chemical
Properties
• As we explore the model placing electrons
in shells, we will see that the pattern which
emerges from this placement correlates well
with a pattern for various chemical
properties
• We will see that all elements in a group
have the same number of electrons in their
outermost (or valence) shell
59. 2.5 Electron Arrangement Groups Have Similar Chemical
and the Periodic Table Properties and Appearances
• Examples of different elements that
have similar properties and are all in
group VA
– Nitrogen
– Phosphorus
– Arsenic
– Antimony
– Bismuth
60. 2.5 Electron Arrangement Shorthand Electron
and the Periodic Table Configurations
• Uses noble gas symbols to represent the
inner shell and the outer shell or valance
shell is written after
• Aluminum- full electron configuration is:
1s22s22p63s23p1
What noble gas configuration is this?
•Neon
•Configuration is written: [Ne]3s23p1
61. 2.5 Electron Arrangement
and the Periodic Table • Remember:
– How many subshells are in each
principle energy level?
– There are n subshells in the n principle
energy level.
– How many orbitals are in each
subshell?
– s has 1, p has 3, d has 5, and f has 7
– How many electrons fit in each orbital?
– 2
62. 2.5 Electron Arrangement Shorthand Electron
and the Periodic Table Configuration Examples
• N
• S
• Ti
• Sn
63. 2.5 Electron Arrangement Classification of Elements
and the Periodic Table According to the Type of
Subshells Being Filled
Use this breakdown of the Periodic Table and you can
write the configuration of any element.
64. 2.5 Electron Arrangement
and the Periodic Table Classification of Elements –
by Group
• Representative element: An element in which the
distinguishing electron is found in an s or p
subshell
• Distinguishing electron: The last or highest-
energy electron found in an element
• Transition element: An element in which the
distinguishing electron is found in a d subshell
• Inner-transition element: An element in which
the distinguishing electron is found in a f
subshell
65. 2.6 The Octet Rule
• The noble gases are extremely stable
– Called inert as they don’t readily bond to other
elements
• The stability is due to a full complement of
valence electrons in the outermost s and p
sublevels:
– 2 electrons in the 1s of Helium
– the s and p subshells are full in the outermost
shell of the other noble gases (eight electrons)
66. Octet of Electrons
2.6 The Octet Rule
• Elements in families other than the noble
gases are more reactive
– Strive to achieve a more stable electron
configuration
– Change the number of electrons in the atom to
result in full s and p sublevels
• Stable electron configuration is called the
“noble gas” configuration
67. 2.6 The Octet Rule The Octet Rule
• Octet rule - elements usually react in such a way
as to attain the electron configuration of the noble
gas closest to them in the periodic table
– Elements on the right side of the table move right to the
next noble gas
– Elements on the left side move “backwards” to the
noble gas of the previous row
• Atoms will gain, lose or share electrons in
chemical reactions to attain this more stable
energy state
68. 2.6 The Octet Rule Ion Formation and the Octet Rule
• Metallic elements tend to form positively
charged ions called cations
• Metals tend to lose all their valence
electrons to obtain a configuration of the
noble gas
Na Na+ + e-
Sodium atom Sodium ion
11e-, 1 valence e- 10e-
[Ne]3s1 [Ne]
69. 2.6 The Octet Rule Ion Formation and the Octet Rule
• All atoms of a group lose the same number of
electrons
• Resulting ion has the same number of electrons as
the nearest (previous) noble gas atom
Al Al3+ + 3e-
Aluminum atom Aluminum ion
13e-, 3 valence e- 10e-
[Ne]3s23p1 [Ne]
70. Isoelectronic
• Isoelectronic - atoms of different elements having
2.6 The Octet Rule
the same electron configuration (same number of
electrons)
• Nonmetallic elements, located on the right side of
the periodic table, tend to form negatively charged
ions called anions
• Nonmetals tend to gain electrons so they become
isoelectronic with its nearest noble gas neighbor
located in the same period to the right
O + 2e- O2-
Oxygen atom Oxide ion
8e-, 6 valence e- 10e-
[He]2s22p4 [He]2s22p6 or [Ne]
71. 2.6 The Octet Rule Using the Octet Rule
• The octet rule is very helpful in predicting
the charges of ions in the representative
elements
• Transition metals still tend to lose electrons
to become cations but predicting the charge
is not as easy
• Transition metals often form more than one
stable ion
– Iron forming Fe2+ and Fe3+ is a common example
72. Examples Using the Octet Rule
2.6 The Octet Rule
• Give the charge of the • Which of the
most probable ion following pairs of
resulting from these atoms and ions are
elements isoelectronic?
– Ca – Cl-, Ar
– Sr – Na+, Ne
– S – Mg2+, Na+
– P – O2-, F-
73. 2.7 Trends in the Periodic Table
• Many atomic properties correlate with
electronic structure and so also with their
position in the periodic table
– atomic size
– ion size
– ionization energy
– electron affinity
74. Atomic Size
2.7 Trends in the Periodic
• The size of an element increases, moving
down from top to bottom of a group
• The valence shell is higher in energy and
Table
farther from the nucleus traveling down the
group
• The size of an element decreases from left
to right across a period
• The increase in magnitude of positive charge
in nucleus pulls the electrons closer to the
nucleus
75. 2.7 Trends in the Periodic
Table Variation in Size of Atoms
76. Cation Size
2.7 Trends in the Periodic
Cations are smaller than their parent atom
• More protons than electrons creates an increased
nuclear charge
• Extra protons pull the remaining electrons closer
to the nucleus
Table
• Ions with multiple positive charges are even
smaller than the corresponding monopositive
ions
– Which would be smaller, Fe2+ or Fe3+? Fe3+
• When a cation is formed isoelectronic with a
noble gas the valence shell is lost, decreasing the
diameter of the ion relative to the parent atom
77. Anion Size
2.7 Trends in the Periodic
Anions are larger than their parent
atom.
• Anions have more electrons than protons
Table
• Excess negative charge reduces the pull
of the nucleus on each individual electron
• Ions with multiple negative charges are
even larger than the corresponding
monopositive ions
78. 2.7 Trends in the Periodic
Relative Size of Select Ions and
Their Parent Atoms
Table
79. 2.7 Trends in the Periodic Ionization Energy
• Ionization energy - The energy required to
remove an electron from an isolated atom
• The magnitude of ionization energy
Table
correlates with the strength of the attractive
force between the nucleus and the
outermost electron
• The lower the ionization energy, the easier
it is to form a cation
ionization energy + Na Na+ + e-
80. Ionization Energy of Select Elements
2.7 Trends in the Periodic
Table
• Ionization decreases down a family as the
outermost electrons are farther from the nucleus
• Ionization increases across a period because the
outermost electrons are more tightly held
• Why would the noble gases be so unreactive?
81. 2.7 Trends in the Periodic Electron Affinity
• Electron affinity - The energy released
when a single electron is added to an
isolated atom
Table
• Electron affinity gives information about
the ease of anion formation
– Large electron affinity indicates an atom
becomes more stable as it forms an anion
Br + e– Br– + energy
82. 2.7 Trends in the Periodic Periodic Trends in Electron
Affinity
• Electron affinity
generally
Table
decreases down a
group
• Electron affinity
generally increases
across a period