This document provides a history of the periodic table and the discoveries that led to its development. It describes early work by Lavoisier, Dalton and others to identify and classify elements. It then outlines key contributions and periodic law proposals by Newlands, Meyer, Mendeleev and others in the 19th century. This included Mendeleev leaving gaps for undiscovered elements and successfully predicting the properties of several. The document also notes early periodicity work by others like Berzelius, Prout, Döbereiner and Gibbes.
The Periodic Classification of the Elements HistoryLatif Hyder Wadho
The document summarizes the development of the periodic table of elements from the early 18th century to the late 19th century. It describes key contributors including Lavoisier who listed the first 33 elements in 1789, Dalton who proposed the atomic theory in 1808, Döbereiner who grouped elements into triads in 1829, de Chancourtois who arranged elements in a spiral in 1862, Newlands who proposed the law of octaves in 1865, and Mendeleev who developed the first recognizable periodic table and made accurate predictions about undiscovered elements in 1869. It also discusses Meyer who independently recognized periodicity in 1864 and Gibbes who developed an early periodic table in the 1870s.
Geochemistry studies the chemical composition and properties of rocks. It examines the distribution and behavior of chemical elements within the Earth's crust. The periodic table evolved over time as scientists like Döbereiner grouped elements into triads based on their atomic weights, and Mendeleev arranged the known elements into the first periodic table based on recurring trends in their properties. This allowed prediction of properties of yet-to-be discovered elements and established atomic weight as the basis for organization until Moseley showed atomic number provided an even more systematic relationship.
This document discusses the history of atomic theory from ancient Indian and Greek philosophers hypothesizing about the divisibility of matter, to Democritus coining the term "atom" to refer to indivisible particles of matter. It then discusses Antoine Lavoisier establishing the laws of chemical combination including the law of conservation of mass and the law of constant proportions. John Dalton later provided his atomic theory, hypothesizing that all matter is made of atoms which are indivisible, identical for a given element, and combine in simple whole number ratios. The document then discusses concepts like atomic mass, molecules, ions, writing chemical formulas, and introduces the mole concept.
Atomic Structure and the Periodic TablePaul Schumann
This document provides an overview of the history and development of atomic theory, including key discoveries and models. It describes early ideas from Democritus and Aristotle, foundations laid by laws of conservation of mass, definite proportions, and multiple proportions. Developments include Dalton's atomic theory, discovery of the electron, proton, neutron, isotopes, and the nuclear model of the atom. The periodic table is introduced along with atomic number, mass number, and calculating average atomic mass.
This document summarizes the history of discoveries that led to the modern understanding of the structure of the atom. It describes early theories proposed by philosophers like Democritus, followed by scientific experiments and findings in the 18th-19th centuries that established laws of chemistry. These included evidence that elements combine in fixed proportions (Dalton) and the law of conservation of mass (Lavoisier). Experiments in the early 1900s using cathode ray tubes led Thomson to discover the electron. Millikan's oil drop experiment precisely measured the charge on electrons. Rutherford's gold foil experiment revealed the tiny, dense nucleus at the center of atoms. Neutrons were later discovered inside atomic nuclei.
Best PowerPoint presentation on NCERT class 9 Atoms and Molecules as per CBSE syllabus it covers full chapter with all information.
By Raxit Gupta
9C
KENDRIYA VIDYALAYA BALLYGUNGE
PowerPoint Presentation on the topic - 'Atoms And Molecules'.
For Class:- 9th
Created By - 'Neha Rohtagi'.
I hope that you will found this presentation useful and it will help you out for your concept understanding.
Thank You!
Please give feedbacks and suggestions to get presentations on more interesting topics.
1. The document discusses the history and development of the periodic table, from early classification systems to modern versions.
2. Early scientists like Dobereiner and Newlands attempted to classify elements based on recurring properties but their systems had limitations.
3. Mendeleev organized the known elements into the first recognizable periodic table based on increasing atomic mass in 1869, allowing predictions of new elements.
4. Modern periodic tables are organized by atomic number instead of mass, reflecting the internal structure of atoms more accurately.
The Periodic Classification of the Elements HistoryLatif Hyder Wadho
The document summarizes the development of the periodic table of elements from the early 18th century to the late 19th century. It describes key contributors including Lavoisier who listed the first 33 elements in 1789, Dalton who proposed the atomic theory in 1808, Döbereiner who grouped elements into triads in 1829, de Chancourtois who arranged elements in a spiral in 1862, Newlands who proposed the law of octaves in 1865, and Mendeleev who developed the first recognizable periodic table and made accurate predictions about undiscovered elements in 1869. It also discusses Meyer who independently recognized periodicity in 1864 and Gibbes who developed an early periodic table in the 1870s.
Geochemistry studies the chemical composition and properties of rocks. It examines the distribution and behavior of chemical elements within the Earth's crust. The periodic table evolved over time as scientists like Döbereiner grouped elements into triads based on their atomic weights, and Mendeleev arranged the known elements into the first periodic table based on recurring trends in their properties. This allowed prediction of properties of yet-to-be discovered elements and established atomic weight as the basis for organization until Moseley showed atomic number provided an even more systematic relationship.
This document discusses the history of atomic theory from ancient Indian and Greek philosophers hypothesizing about the divisibility of matter, to Democritus coining the term "atom" to refer to indivisible particles of matter. It then discusses Antoine Lavoisier establishing the laws of chemical combination including the law of conservation of mass and the law of constant proportions. John Dalton later provided his atomic theory, hypothesizing that all matter is made of atoms which are indivisible, identical for a given element, and combine in simple whole number ratios. The document then discusses concepts like atomic mass, molecules, ions, writing chemical formulas, and introduces the mole concept.
Atomic Structure and the Periodic TablePaul Schumann
This document provides an overview of the history and development of atomic theory, including key discoveries and models. It describes early ideas from Democritus and Aristotle, foundations laid by laws of conservation of mass, definite proportions, and multiple proportions. Developments include Dalton's atomic theory, discovery of the electron, proton, neutron, isotopes, and the nuclear model of the atom. The periodic table is introduced along with atomic number, mass number, and calculating average atomic mass.
This document summarizes the history of discoveries that led to the modern understanding of the structure of the atom. It describes early theories proposed by philosophers like Democritus, followed by scientific experiments and findings in the 18th-19th centuries that established laws of chemistry. These included evidence that elements combine in fixed proportions (Dalton) and the law of conservation of mass (Lavoisier). Experiments in the early 1900s using cathode ray tubes led Thomson to discover the electron. Millikan's oil drop experiment precisely measured the charge on electrons. Rutherford's gold foil experiment revealed the tiny, dense nucleus at the center of atoms. Neutrons were later discovered inside atomic nuclei.
Best PowerPoint presentation on NCERT class 9 Atoms and Molecules as per CBSE syllabus it covers full chapter with all information.
By Raxit Gupta
9C
KENDRIYA VIDYALAYA BALLYGUNGE
PowerPoint Presentation on the topic - 'Atoms And Molecules'.
For Class:- 9th
Created By - 'Neha Rohtagi'.
I hope that you will found this presentation useful and it will help you out for your concept understanding.
Thank You!
Please give feedbacks and suggestions to get presentations on more interesting topics.
1. The document discusses the history and development of the periodic table, from early classification systems to modern versions.
2. Early scientists like Dobereiner and Newlands attempted to classify elements based on recurring properties but their systems had limitations.
3. Mendeleev organized the known elements into the first recognizable periodic table based on increasing atomic mass in 1869, allowing predictions of new elements.
4. Modern periodic tables are organized by atomic number instead of mass, reflecting the internal structure of atoms more accurately.
The document discusses the history and development of the periodic table. It describes early classification systems by Dobereiner, Newlands, and Meyer that recognized patterns in element properties but had limitations. Mendeleev created the first successful periodic table in 1869 by arranging elements by atomic mass and leaving gaps for undiscovered elements. Moseley established in 1913 that atomic number, not mass, is fundamental; the modern periodic table is based on atomic number.
Historical development of periodic tableVeenuGupta8
THIS PRESENTATION IS BASED ON THE CONTRIBUTION OF DIFFERENT CHEMIST IN CREATING THE PERIODIC TABLE .IT WILL HELP THE LEARN THE VARIOUS MERITS AND DEMERITS OF VARIOUS METHODS OF CLASSIFYING ELEMENTS
John Dalton formulated his atomic theory in the early 1800s based on careful chemical measurements and observations. His theory proposed that (1) all matter is composed of tiny indivisible atoms, (2) atoms of the same element are identical in mass, (3) atoms of different elements have different masses, and (4) atoms combine in simple whole number ratios. Dalton's atomic theory provided the foundation for modern chemistry and physics by establishing that elements combine at the atomic level. While Dalton's model has been refined over time, it represented a revolutionary shift in understanding the basic nature of matter.
Periodic classification of elements 10 CHM(5)VeenuGupta8
THIS PRESENTATION IS BASED ON THE PERIODIC CLASSIFICATION OF ELEMENTS AND THE VARIATION OF THE PERIODIC PROPERTIES IN THE PERIODIC TABLE.IT IS EASY TO GET KNOWLEDGE ABOUT THE PERIODIC PROPERTIES.
CHM021 5 GROSS STRUCTURE OF ATOM (model).pptxYaySandoval1
1. The document discusses the early theories of matter composition from the Greeks to Dalton's atomic theory. It then summarizes evidence from experiments in the late 19th to early 20th century that led to discoveries of the internal structure of atoms, including discovery of the electron, proton, and neutron.
2. Key experiments and scientists discussed include Thomson's discovery of the electron, Millikan's measurement of the electron's charge, Rutherford's nuclear model of the atom based on radioactive experiments, discovery of the proton by Goldstein and Chadwick's discovery of the neutron.
3. These discoveries revealed that atoms are mostly empty space with a small, dense nucleus containing protons and neutrons, and electrons in orbits around
Döbereiner and Newland’s classification of elementsAfrah Aamer
A Powerpoint made for my school on Döbereiner and Newland’s classification of elements describing and explaining the different patterns and structures in which the Elements were arranged before we encountered the Periodic Table of Elements as we know them today.
Also a Fun Fact:
The 4 newest elements on the periodic table have just been named:
-Nihonium and symbol Nh, for the element with Z =113,
-Moscovium with the symbol Mc, for the element with Z = 115,
-Tennessine with the symbol Ts, for the element with Z = 117,
-Oganesson with the symbol Og, for the element with Z = 118.
The document discusses the development of the periodic table. It describes early attempts by scientists like Dobereiner, de Chancourtois, and Newlands to classify and organize the known chemical elements. It then focuses on the key contributions of Dmitri Mendeleev and Lothar Meyer, who independently proposed the periodic law stating that properties of elements are periodic functions of their atomic weights. Mendeleev is credited with publishing the first recognizable version of the modern periodic table in 1869, arranging elements by property groups and leaving gaps for undiscovered elements, some of which he accurately predicted properties for like gallium and germanium. His work established the periodic table as essential for classifying and understanding the elements.
The document provides an overview of the historical development of atomic models from ancient Greek philosophers to modern quantum theory. It discusses early theories proposed by Empedocles, Democritus, and Aristotle. It then outlines key contributions from alchemists, Boyle, Priestley, Lavoisier, Cavendish, Dalton, Thomson, Rutherford, Bohr, Moseley, and Chadwick that led to modern atomic structure including the discovery of subatomic particles like protons, neutrons, and electrons. The document also defines important atomic concepts like atomic number, mass number, isotopes, and how to determine the number of each subatomic particle in an atom.
The periodic table, also known as the periodic table of elements, is a tabular display of the chemical elements, which are arranged by atomic number, electron configuration, and recurring chemical properties. The structure of the table shows periodic trends.
This document provides an overview of early atomic theory and the development of modern atomic structure and chemical bonding models. It discusses the Greek concept of atoms, early atomic theories of Democritus and Dalton, experiments by Thomson, Rutherford and others that led to discovery of the electron and nuclear atom, and development of the periodic table. Key concepts introduced include atoms, molecules, ions, isomers, naming binary compounds and acids.
The document discusses the history and development of atomic theory from ancient Greek philosophers to modern atomic structure. Some key points covered include:
- Democritus first proposed the idea of atoms in ancient Greece but lacked evidence.
- In the 1800s, Dalton proposed his atomic theory that elements are made of atoms that combine in simple whole number ratios.
- Advances revealed atoms have internal structure including a tiny dense nucleus and orbiting electrons.
- Atoms are identified by their atomic number and mass number, which indicate protons, neutrons, and isotopes.
- The mole, molar mass, and Avogadro's number allow relating masses to numbers of atoms and particles.
The document summarizes key aspects of the periodic table, including its history, development, structure, and organization. It discusses the discovery of elements and early classification attempts by scientists like Döbereiner and Newlands. It then describes Mendeleev's development of the periodic table and its completion with noble gases. The summary defines the modern periodic table's groups and periods based on electron configuration. It also briefly discusses the blocks and provides definitions of acids and bases.
Dmitri Mendeleyev was a Russian chemist known for creating the first version of the periodic table of elements in 1869, in which he arranged the elements in order of atomic weight and was able to predict the properties and existence of undiscovered elements. He organized the known elements into the first recognizable periodic table, which grouped elements with similar properties together and left space for elements not yet discovered; this table was a fundamental contribution to chemistry that allowed prediction of new elements. Mendeleyev arranged the elements in order of atomic weight and grouped them by similarity of properties, allowing him to predict the existence and properties of several elements before their actual discovery
The document discusses the early discoveries that led to the modern atomic theory, including Thomson's discovery of the electron in 1897, Rutherford's experiments with radioactive elements which established that atoms have a small, dense nucleus, and Rutherford's gold foil experiment in 1911 which demonstrated that the mass and positive charge of atoms are concentrated in a tiny nucleus rather than uniformly distributed as previously thought. These experiments revealed that atoms are made up of a small, positively charged nucleus surrounded by electrons and established the basic structure of atoms that forms the basis of modern atomic theory.
This document provides an overview of atomic theory and basic concepts in chemistry including:
1) Dalton's atomic theory which states that matter is made of extremely small indivisible particles called atoms.
2) Atoms of different elements have different properties and atoms of the same element are identical.
3) Chemical reactions involve changes in how atoms are combined but atoms themselves are neither created nor destroyed.
4) The discovery of subatomic particles like electrons, protons and neutrons led to Rutherford's nuclear model of the atom.
5) Isotopes are atoms of the same element with different numbers of neutrons. The periodic table organizes elements by atomic number.
This document provides an overview of atomic theory and basic concepts in chemistry including:
1) Dalton's atomic theory which states that matter is made of extremely small indivisible particles called atoms.
2) Atoms of different elements have different properties and atoms of the same element are identical.
3) Chemical reactions involve changes in how atoms are combined, not in the atoms themselves.
4) The discovery of subatomic particles like electrons, protons and neutrons led to Rutherford's nuclear model of the atom with a small, dense nucleus.
5) The periodic table organizes elements based on atomic structure including atomic number and recurring trends in properties.
Concepto y estructura del átomo, historia del átomo, modelos atómicos de Dalton, Thomson, Rutherford, Bohr así como sus inconvenientes. Descripción de los experimentos que condujeron al descubrimientos del electrón, protón y neutrón.
Descripción de las características generales de los espectros atómicos y el modelos mecano cuántico, orbitales y números cuánticos.
The document discusses the history and properties of atoms. It describes atoms as the smallest unit of matter, first proposed by Greek philosophers. John Dalton established atoms as the building blocks of elements with unique properties. The structure of atoms was further elucidated by scientists like Thomson, Rutherford, Bohr, and Schrodinger, who discovered atoms have a tiny, dense nucleus surrounded by orbiting electrons. Atoms bond through ionic, covalent, and metallic bonds to form molecules and matter in various states. Matter is anything that has mass and occupies space, and can be transformed between different states while obeying the law of conservation of matter.
Atoms are the smallest particles that make up all matter. John Dalton's atomic theory states that all matter is made of tiny indivisible particles called atoms. Atoms of different elements have different masses and chemical properties. Two or more atoms can combine to form molecules, which are the smallest units that retain the properties of a substance. Molecules are formed when atoms bond together via chemical bonds and are the smallest particles that can exist independently. Common examples of molecules include water (H2O) and oxygen (O2).
This document discusses concepts related to motion including position, relative and absolute position, distance and displacement, speed and velocity, uniform and non-uniform motion, and uniformly accelerated motion. It defines key terms and concepts and provides examples to illustrate them. Position can be relative or absolute depending on the reference point used. Distance refers to the total path travelled, while displacement refers to the net or direct distance between two points. Speed is the rate of change of distance and velocity is the rate of change of displacement, making velocity a vector quantity. Uniform motion involves equal distances in equal times while non-uniform motion does not. Uniformly accelerated motion follows three equations of motion and has constant acceleration.
This document provides information about atoms, molecules, ions and chemical formulas. It discusses key concepts such as:
- Dalton's atomic theory which states that matter is made of tiny indivisible particles called atoms that combine in small whole number ratios.
- Atoms have symbols to represent them and an atomic mass that is measured relative to carbon-12. Molecules are groups of atoms that are chemically bonded.
- Chemical formulas show the types and numbers of atoms or ions that make up a compound. Formulas are written with the cation written first followed by the anion.
The document discusses the history and development of the periodic table. It describes early classification systems by Dobereiner, Newlands, and Meyer that recognized patterns in element properties but had limitations. Mendeleev created the first successful periodic table in 1869 by arranging elements by atomic mass and leaving gaps for undiscovered elements. Moseley established in 1913 that atomic number, not mass, is fundamental; the modern periodic table is based on atomic number.
Historical development of periodic tableVeenuGupta8
THIS PRESENTATION IS BASED ON THE CONTRIBUTION OF DIFFERENT CHEMIST IN CREATING THE PERIODIC TABLE .IT WILL HELP THE LEARN THE VARIOUS MERITS AND DEMERITS OF VARIOUS METHODS OF CLASSIFYING ELEMENTS
John Dalton formulated his atomic theory in the early 1800s based on careful chemical measurements and observations. His theory proposed that (1) all matter is composed of tiny indivisible atoms, (2) atoms of the same element are identical in mass, (3) atoms of different elements have different masses, and (4) atoms combine in simple whole number ratios. Dalton's atomic theory provided the foundation for modern chemistry and physics by establishing that elements combine at the atomic level. While Dalton's model has been refined over time, it represented a revolutionary shift in understanding the basic nature of matter.
Periodic classification of elements 10 CHM(5)VeenuGupta8
THIS PRESENTATION IS BASED ON THE PERIODIC CLASSIFICATION OF ELEMENTS AND THE VARIATION OF THE PERIODIC PROPERTIES IN THE PERIODIC TABLE.IT IS EASY TO GET KNOWLEDGE ABOUT THE PERIODIC PROPERTIES.
CHM021 5 GROSS STRUCTURE OF ATOM (model).pptxYaySandoval1
1. The document discusses the early theories of matter composition from the Greeks to Dalton's atomic theory. It then summarizes evidence from experiments in the late 19th to early 20th century that led to discoveries of the internal structure of atoms, including discovery of the electron, proton, and neutron.
2. Key experiments and scientists discussed include Thomson's discovery of the electron, Millikan's measurement of the electron's charge, Rutherford's nuclear model of the atom based on radioactive experiments, discovery of the proton by Goldstein and Chadwick's discovery of the neutron.
3. These discoveries revealed that atoms are mostly empty space with a small, dense nucleus containing protons and neutrons, and electrons in orbits around
Döbereiner and Newland’s classification of elementsAfrah Aamer
A Powerpoint made for my school on Döbereiner and Newland’s classification of elements describing and explaining the different patterns and structures in which the Elements were arranged before we encountered the Periodic Table of Elements as we know them today.
Also a Fun Fact:
The 4 newest elements on the periodic table have just been named:
-Nihonium and symbol Nh, for the element with Z =113,
-Moscovium with the symbol Mc, for the element with Z = 115,
-Tennessine with the symbol Ts, for the element with Z = 117,
-Oganesson with the symbol Og, for the element with Z = 118.
The document discusses the development of the periodic table. It describes early attempts by scientists like Dobereiner, de Chancourtois, and Newlands to classify and organize the known chemical elements. It then focuses on the key contributions of Dmitri Mendeleev and Lothar Meyer, who independently proposed the periodic law stating that properties of elements are periodic functions of their atomic weights. Mendeleev is credited with publishing the first recognizable version of the modern periodic table in 1869, arranging elements by property groups and leaving gaps for undiscovered elements, some of which he accurately predicted properties for like gallium and germanium. His work established the periodic table as essential for classifying and understanding the elements.
The document provides an overview of the historical development of atomic models from ancient Greek philosophers to modern quantum theory. It discusses early theories proposed by Empedocles, Democritus, and Aristotle. It then outlines key contributions from alchemists, Boyle, Priestley, Lavoisier, Cavendish, Dalton, Thomson, Rutherford, Bohr, Moseley, and Chadwick that led to modern atomic structure including the discovery of subatomic particles like protons, neutrons, and electrons. The document also defines important atomic concepts like atomic number, mass number, isotopes, and how to determine the number of each subatomic particle in an atom.
The periodic table, also known as the periodic table of elements, is a tabular display of the chemical elements, which are arranged by atomic number, electron configuration, and recurring chemical properties. The structure of the table shows periodic trends.
This document provides an overview of early atomic theory and the development of modern atomic structure and chemical bonding models. It discusses the Greek concept of atoms, early atomic theories of Democritus and Dalton, experiments by Thomson, Rutherford and others that led to discovery of the electron and nuclear atom, and development of the periodic table. Key concepts introduced include atoms, molecules, ions, isomers, naming binary compounds and acids.
The document discusses the history and development of atomic theory from ancient Greek philosophers to modern atomic structure. Some key points covered include:
- Democritus first proposed the idea of atoms in ancient Greece but lacked evidence.
- In the 1800s, Dalton proposed his atomic theory that elements are made of atoms that combine in simple whole number ratios.
- Advances revealed atoms have internal structure including a tiny dense nucleus and orbiting electrons.
- Atoms are identified by their atomic number and mass number, which indicate protons, neutrons, and isotopes.
- The mole, molar mass, and Avogadro's number allow relating masses to numbers of atoms and particles.
The document summarizes key aspects of the periodic table, including its history, development, structure, and organization. It discusses the discovery of elements and early classification attempts by scientists like Döbereiner and Newlands. It then describes Mendeleev's development of the periodic table and its completion with noble gases. The summary defines the modern periodic table's groups and periods based on electron configuration. It also briefly discusses the blocks and provides definitions of acids and bases.
Dmitri Mendeleyev was a Russian chemist known for creating the first version of the periodic table of elements in 1869, in which he arranged the elements in order of atomic weight and was able to predict the properties and existence of undiscovered elements. He organized the known elements into the first recognizable periodic table, which grouped elements with similar properties together and left space for elements not yet discovered; this table was a fundamental contribution to chemistry that allowed prediction of new elements. Mendeleyev arranged the elements in order of atomic weight and grouped them by similarity of properties, allowing him to predict the existence and properties of several elements before their actual discovery
The document discusses the early discoveries that led to the modern atomic theory, including Thomson's discovery of the electron in 1897, Rutherford's experiments with radioactive elements which established that atoms have a small, dense nucleus, and Rutherford's gold foil experiment in 1911 which demonstrated that the mass and positive charge of atoms are concentrated in a tiny nucleus rather than uniformly distributed as previously thought. These experiments revealed that atoms are made up of a small, positively charged nucleus surrounded by electrons and established the basic structure of atoms that forms the basis of modern atomic theory.
This document provides an overview of atomic theory and basic concepts in chemistry including:
1) Dalton's atomic theory which states that matter is made of extremely small indivisible particles called atoms.
2) Atoms of different elements have different properties and atoms of the same element are identical.
3) Chemical reactions involve changes in how atoms are combined but atoms themselves are neither created nor destroyed.
4) The discovery of subatomic particles like electrons, protons and neutrons led to Rutherford's nuclear model of the atom.
5) Isotopes are atoms of the same element with different numbers of neutrons. The periodic table organizes elements by atomic number.
This document provides an overview of atomic theory and basic concepts in chemistry including:
1) Dalton's atomic theory which states that matter is made of extremely small indivisible particles called atoms.
2) Atoms of different elements have different properties and atoms of the same element are identical.
3) Chemical reactions involve changes in how atoms are combined, not in the atoms themselves.
4) The discovery of subatomic particles like electrons, protons and neutrons led to Rutherford's nuclear model of the atom with a small, dense nucleus.
5) The periodic table organizes elements based on atomic structure including atomic number and recurring trends in properties.
Concepto y estructura del átomo, historia del átomo, modelos atómicos de Dalton, Thomson, Rutherford, Bohr así como sus inconvenientes. Descripción de los experimentos que condujeron al descubrimientos del electrón, protón y neutrón.
Descripción de las características generales de los espectros atómicos y el modelos mecano cuántico, orbitales y números cuánticos.
The document discusses the history and properties of atoms. It describes atoms as the smallest unit of matter, first proposed by Greek philosophers. John Dalton established atoms as the building blocks of elements with unique properties. The structure of atoms was further elucidated by scientists like Thomson, Rutherford, Bohr, and Schrodinger, who discovered atoms have a tiny, dense nucleus surrounded by orbiting electrons. Atoms bond through ionic, covalent, and metallic bonds to form molecules and matter in various states. Matter is anything that has mass and occupies space, and can be transformed between different states while obeying the law of conservation of matter.
Atoms are the smallest particles that make up all matter. John Dalton's atomic theory states that all matter is made of tiny indivisible particles called atoms. Atoms of different elements have different masses and chemical properties. Two or more atoms can combine to form molecules, which are the smallest units that retain the properties of a substance. Molecules are formed when atoms bond together via chemical bonds and are the smallest particles that can exist independently. Common examples of molecules include water (H2O) and oxygen (O2).
Similar to Periodic Classification - History.ppt (20)
This document discusses concepts related to motion including position, relative and absolute position, distance and displacement, speed and velocity, uniform and non-uniform motion, and uniformly accelerated motion. It defines key terms and concepts and provides examples to illustrate them. Position can be relative or absolute depending on the reference point used. Distance refers to the total path travelled, while displacement refers to the net or direct distance between two points. Speed is the rate of change of distance and velocity is the rate of change of displacement, making velocity a vector quantity. Uniform motion involves equal distances in equal times while non-uniform motion does not. Uniformly accelerated motion follows three equations of motion and has constant acceleration.
This document provides information about atoms, molecules, ions and chemical formulas. It discusses key concepts such as:
- Dalton's atomic theory which states that matter is made of tiny indivisible particles called atoms that combine in small whole number ratios.
- Atoms have symbols to represent them and an atomic mass that is measured relative to carbon-12. Molecules are groups of atoms that are chemically bonded.
- Chemical formulas show the types and numbers of atoms or ions that make up a compound. Formulas are written with the cation written first followed by the anion.
1. The document discusses concepts related to gravitation including Newton's Universal Law of Gravitation, Kepler's Laws of Planetary Motion, gravitational force, and acceleration due to gravity.
2. Key points covered include Newton's inverse square law formula for gravitational force, Kepler's three laws of planetary motion, and definitions of free fall and acceleration due to gravity.
3. The document also discusses properties of gravitational force and provides examples to illustrate concepts like why objects on Earth do not continuously accelerate towards each other due to gravitational attraction.
This document defines key concepts in matter, including:
- Matter is anything that has mass and occupies space, and can be made of elements, molecules, or compounds.
- Elements are the simplest forms of matter and cannot be broken down further into simpler substances. Atoms are the smallest particle of an element.
- Atoms bond together to form molecules or bond with different elements to form compounds like salt or water.
- All matter is made of atoms in constant motion according to kinetic theory. Atoms are arranged in the periodic table by atomic number.
- Atoms contain a nucleus of protons and neutrons, with electrons orbiting the nucleus in shells. The number of protons determines the element.
This document defines key concepts in matter, including:
- Matter is anything that has mass and occupies space, and can be made of elements, molecules, or compounds.
- Elements are the simplest forms of matter and cannot be broken down further into simpler substances. Atoms are the smallest particle of an element.
- Atoms bond together to form molecules or bond with different elements to form compounds like salt or water.
- All matter is made of atoms that are always in motion according to kinetic theory. Heavier atoms move slower than lighter ones.
- The periodic table organizes all known elements by their atomic structure.
This document provides an overview of the classification of living organisms. It discusses the need for classification, the basis used for classification including cell structure and nutrition type, and the hierarchical system used from kingdoms down to species. The five kingdom system is described, including Monera, Protista, Fungi, Plantae, and Animalia. Details are given on the classification of plants into five groups and animals into ten groups, with examples provided. The classification of living organisms arranges organisms into taxonomic groups based on similarities to allow for organized study.
Sound is a form of energy that propagates as longitudinal waves, requiring a medium. It is produced by vibrating objects and transmitted through compression and rarefaction variations in the medium. The human ear can detect sounds between 20 Hz to 20 kHz. Ultrasound with frequencies above this range has applications like medical imaging and industrial cleaning, while infrasound below 20 Hz is used for communication by some animals. Sonar uses ultrasound for underwater detection of objects.
The document discusses natural resources and the four main spheres of Earth - the lithosphere, hydrosphere, atmosphere, and biosphere. It describes each sphere and their composition. The document then discusses various natural resources like air, water, soil minerals, and their importance. It also discusses pollution of these resources and processes like the water cycle and biogeochemical cycles.
This document discusses factors related to health and disease. It defines health as a state of complete physical, mental and social well-being. Important characteristics of good health include being free from sickness, anxiety, and tensions. Health can fail due to poor physical/social environments, economic conditions, or lack of social equality. The document distinguishes between "healthy" and "disease-free," and outlines different types of diseases including acute, chronic, infectious/communicable, and non-infectious/non-communicable diseases. It describes causes of disease such as pathogens, genetic disorders, pollution and malnutrition. Means of disease transmission include air, water, food, vectors, contact and sexual contact. Principles of treatment are to
Here are the answers:
a) Disease is an abnormal condition affecting the body or mind that impairs normal functioning and causes discomfort.
b) The two major categories of human diseases are:
1. Infectious diseases - caused by pathogens like bacteria, viruses, fungi or parasites.
Examples: Malaria (caused by protozoan Plasmodium), Tuberculosis (caused by bacteria Mycobacterium tuberculosis)
2. Non-infectious diseases - not caused by pathogens. Develop due to genetic reasons, unhealthy lifestyle or environmental factors.
Examples: Cancer (uncontrolled cell growth), Heart disease (caused by risk factors like hypertension, smoking, obesity)
Here are the answers:
a) Disease is an abnormal condition affecting the body or mind that impairs normal functioning and causes discomfort.
b) The two major categories of human diseases are:
1. Infectious diseases - caused by pathogens like bacteria, viruses, fungi or parasites.
Examples: Malaria (caused by a protozoan parasite), Tuberculosis (caused by Mycobacterium tuberculosis bacteria)
2. Non-infectious diseases - not caused by pathogens. These include genetic diseases, cancer, heart diseases, mental illnesses etc.
Examples: Diabetes (caused due to malfunctioning of pancreas), Asthma (caused due to hypersensitivity of airways
Here are the key causes of cancer:
- Genetic factors - Some people inherit gene mutations from their parents that increase their risk of certain cancers.
- Tobacco use - Smoking or chewing tobacco is linked to cancers of the lung, esophagus, larynx, mouth, bladder, kidney, liver, stomach, pancreas, and colon/rectum. Tobacco contains chemicals that can damage DNA.
- Diet and obesity - A diet high in red/processed meats and low in fruits and vegetables increases cancer risk. Obesity is linked to several cancers. Excess weight increases hormone levels and inflammation.
- Radiation - Both natural sources like radon and man-made sources like X-rays can damage
Here are the key causes of cancer:
- Genetic factors - Some people inherit gene mutations from their parents that increase their risk of certain cancers.
- Tobacco use - Smoking or chewing tobacco is linked to cancers of the lung, esophagus, larynx, mouth, bladder, kidney, liver, stomach, pancreas, colon and rectum, and acute myeloid leukemia.
- Diet and obesity - A diet high in red/processed meats and low in fruits and vegetables increases the risk of several cancers. Obesity is linked to increased risk of multiple cancers.
- Alcohol use - Heavy drinking is linked to cancers of the mouth, esophagus, throat, liver and breast.
-
Sound is a form of energy that propagates as longitudinal waves, requiring a medium. It is produced by vibrating objects and transmitted through compression and rarefaction variations in the medium. The human ear can detect sounds between 20 Hz to 20 kHz. Ultrasound with frequencies above this range has applications like medical imaging and material cleaning, while infrasound below 20 Hz is used by some animals. Sonar also uses ultrasound for underwater object detection.
1. The document discusses Heinrich Hertz's experiments with sound and how it is produced through vibration and propagates as longitudinal waves through a medium like air.
2. Key experiments shown include using a vibrating tuning fork to produce compressions and rarefactions in air, demonstrating that sound needs a material medium to travel, and that the speed of sound depends on the medium and temperature.
3. Applications of sound reflection, resonance, infrasound, ultrasound, and SONAR are also summarized.
This document describes various concepts related to motion including:
1. Motion is defined as the change in position of a body over time. Distance moved is the total path travelled, while displacement is the shortest distance between initial and final positions.
2. Uniform motion means equal distances are travelled in equal times, while non-uniform motion means unequal distances in equal times. Examples of each are given.
3. Speed, velocity, average speed, average velocity, acceleration, and equations of motion relating these quantities are defined and explained with examples. Distance-time graphs and their use in representing motion are also described.
This document provides an overview of the classification of living organisms. It discusses the need for classification, the basis used for classification including cell structure and nutrition type, and the hierarchical system used from kingdoms down to species. The five kingdom system is described, including Monera, Protista, Fungi, Plantae, and Animalia. An overview of the classification of plants and animals is also provided, outlining the main groups within each kingdom.
1. Biodiversity refers to the variety of living organisms on Earth, including plants, animals, and microorganisms. 2. Taxonomy is the science of classifying organisms using their similarities and differences. A key aspect is assigning each organism a unique scientific name. 3. The binomial system of nomenclature assigns every organism a genus and species name, allowing for uniform identification worldwide.
Plants and animals are made of different types of tissues due to differences in their structure and function. In multicellular organisms, cells are grouped together into tissues to efficiently perform specialized functions. In plants, tissues include epidermis, a protective outer layer of flat cells covered with a waxy cuticle. Meristematic tissues contain actively dividing cells and produce permanent tissues through differentiation. Permanent tissues include parenchyma, collenchyma, and sclerenchyma, which provide structure and support to plants. Stomata in the leaf epidermis allow for gas exchange and transpiration. As plants age, cork replaces the epidermis and protects the bark.
Reimagining Your Library Space: How to Increase the Vibes in Your Library No ...Diana Rendina
Librarians are leading the way in creating future-ready citizens – now we need to update our spaces to match. In this session, attendees will get inspiration for transforming their library spaces. You’ll learn how to survey students and patrons, create a focus group, and use design thinking to brainstorm ideas for your space. We’ll discuss budget friendly ways to change your space as well as how to find funding. No matter where you’re at, you’ll find ideas for reimagining your space in this session.
This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
How to Setup Warehouse & Location in Odoo 17 InventoryCeline George
In this slide, we'll explore how to set up warehouses and locations in Odoo 17 Inventory. This will help us manage our stock effectively, track inventory levels, and streamline warehouse operations.
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
Leveraging Generative AI to Drive Nonprofit InnovationTechSoup
In this webinar, participants learned how to utilize Generative AI to streamline operations and elevate member engagement. Amazon Web Service experts provided a customer specific use cases and dived into low/no-code tools that are quick and easy to deploy through Amazon Web Service (AWS.)
Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
"Learn about all the ways Walmart supports nonprofit organizations.
You will hear from Liz Willett, the Head of Nonprofits, and hear about what Walmart is doing to help nonprofits, including Walmart Business and Spark Good. Walmart Business+ is a new offer for nonprofits that offers discounts and also streamlines nonprofits order and expense tracking, saving time and money.
The webinar may also give some examples on how nonprofits can best leverage Walmart Business+.
The event will cover the following::
Walmart Business + (https://business.walmart.com/plus) is a new shopping experience for nonprofits, schools, and local business customers that connects an exclusive online shopping experience to stores. Benefits include free delivery and shipping, a 'Spend Analytics” feature, special discounts, deals and tax-exempt shopping.
Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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Find out more about ISO training and certification services
Training: ISO/IEC 27001 Information Security Management System - EN | PECB
ISO/IEC 42001 Artificial Intelligence Management System - EN | PECB
General Data Protection Regulation (GDPR) - Training Courses - EN | PECB
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1. History on PowerPoint:
The Periodic Classification
of the Elements
David A. Katz
Department of Chemistry
Pima Community College – West Campus
2202 W. anklam Rd.
Tucson, AZ 85709 USA
Email: dkatz@pima.edu
3. Antoine Lavoisier
(1743-1797)
Listed 33 Substances
Simples (elements) in his
Traité Élémentaire de
Chimie (1789)
In his list are included light
(lumière) and caloric
(calorique), which he
believed to be material
substances.
4. The Atomic Theory
• John Dalton (1766-1844)
– New System of Chemical
Philosophy, 1808
– All bodies are constituted of a vast
number of extremely small
particles, or atoms of matter bound
together by a force of attraction
– The ultimate particles of all
homogeneous bodies are perfectly
alike in weight, figure, etc.
5. The Atomic Theory
– Atoms have definite relative weights “expressed in
atoms of hydrogen, each of which is denoted by
unity”
– Atoms combine in simple numerical ratios to form
compounds
– Under given experimental conditions a particular
atom will always behave in the same manner
– Atoms are indestructible
7. Jöns Jakob Berzelius (1779-1848)
From Annals of Philosophy 2, 443-454 (1813), 3, 51-2, 93-106, 244-255,
353-364 (1814):
The chemical signs ought to be letters, for the greater facility of
writing, and not to disfigure a printed book. Though this last
circumstance may not appear of any great importance, it ought to be
avoided whenever it can be done. I shall take, therefore, for the
chemical sign, the initial letter of the Latin name of each elementary
substance: but as several have the same initial letter, I shall
distinguish them in the following manner:
1. In the class which I call metalloids, I shall employ the
initial letter only, even when this letter is common to the
metalloid and some metal.
2. In the class of metals, I shall distinguish those that have
the same initials with another metal, or a metalloid, by
writing the first two letters of the word.
3. If the first two letters be common to two metals, I shall,
in that case, add to the initial letter the first consonant which
they have not in common: for example, S = sulphur,
Si = silicium, St = stibium (antimony), Sn = stannum (tin),
C = carbonicum, Co = cobaltum (cobalt), Cu = cuprum (copper),
O = oxygen, Os = osmium, &c.
8. Name Symbol Name Symbol Name Symbol Name Symbol
Oxygen O Tungsten Tn Palladium Pa Uranium U
Sulphur S Antimony Sb Silver Ag Cerium Ce
Phosphorus P Tellurium Te Mercury Hg Yttrium Y
Muriatic
radicle
(chlorine)
M
Columbium
(nioblium)
Cl Copper Cu
Glucinum
(beryllium)
Gl
Fluoric
radicle
F Titanium Ti Nickel Ni Aluminum Al
Boron B Zirconium Zr Cobalt Co Magnesium Ms
Carbon C Silicium Si Bismuth Bi Strontium Sr
Nitric radicle N Osmium Os Lead Pb Barytium Ba
Hydrogen H Iridium I Tin Sn Calcium Ca
Arsenic As Rhodium Rh Iron Fe Sodium So
Molybdenum Mo Platinum Pt Zinc Zn Potassium Po
Chromium Ch Gold Au Manganese Ma
Elements known to Berzelius
9. William Prout (1785-1850)
Prout’s Hypothesis:
In two papers On the Relation between the Specific
Gravities of Bodies in their Gaseous State and the
Weights of their Atoms (Annals of Philosophy, 1815,
1816), Prout hypothesized that the atomic weight of
every element is an integer multiple of that of
hydrogen, suggesting that the hydrogen is the
fundamental particle that the atoms of other elements
are made.
“If the view we have ventured to advance be correct, we may almost consider the πρωτη
υλη (tr.: primal matter) of the ancients to be realised in hydrogen; an opinion, by the by, not
altogether new. If we actually consider this to be the case, and further consider the specific
gravities of bodies in their gaseous state to represent the number of volumes condensed into
one; or, in other words, the number of the absolute weight of a single volume of the first
matter (πρωτη υλη) which they contain, which is extremely probable, multiples in weight
must always indicate multiples in volume, and vice versa; and the specific gravities, or
absolute weights of all bodies in a gaseous state, must be multiples of the specific gravity or
absolute weight of the first matter (πρωτη υλη), because all bodies in a gaseous state which
unite with one another unite with reference to their volume.”
10. Johann Wolfgang Döbereiner (1780-1849)
Examples of Döbereiner’ Triads:
“…the atomic weight of bromine might be the arithmetical mean of the atomic
weights of chlorine and iodine. This mean is (35.470+126.470)/2 = 80.470 This
number is not much greater than that found by Berzelius (78.383)”
Using modern values: Cl = 35.45
Br = 79.90
I = 126.90
Döbereiner’ Triads:
In his paper, An Attempt to Group Elementary
Substances according to Their Analogies
(Poggendorf's Annalen der Physik und Chemie, 1829),
Döbereiner grouped elements to show that atomic
weights of a middle element were an average of two
similar elements.
11. Examples of Döbereiner’ Triads: (continued)
“…the specific gravity and atomic weight of strontia are very close to the arithmetic mean of
the specific gravities and atomic weights of lime and baryta, since
[356.019(=Ca.)+956.880(=Ba.)]/2 = 656.449(=Sr.) and the actual value for strontia is 647.285. “
Using modern values: Ca = 40.08
Sr = 87.62
Ba = 137.33
“In the alkali group, according to this view, soda stands in the middle, since if we take the value
for the atomic weight of lithia, determined by Gmelin, = 195.310, and the value for potash =
589.916, then the arithmetic mean of these numbers, (195.310+589.916)/2 = 392.613,which
comes very close to the atomic value for soda, which Berzelius determined as = 390.897.”
Using modern values: Li = 6.94
Na = 22.99
K = 39.10
“If sulfur, selenium, and tellurium belong to one group, which can well be assumed, since the
specific gravity of selenium is exactly the arithmetic mean of the specific gravities of sulfur and
tellurium, and all three substances combine with hydrogen to form characteristic hydrogen
acids, then selenium forms the middle member, since [32.239(=S) + 129.243(=Te)]/2 = 80.741
and the empirically found atomic value for selenium is 79.263.”
Using modern values: S = 32.07
Se = 78.96
Te = 127.60
12. Alexandre-Émile Béguyer de
Chancourtois (1820-1886)
The Telluric Helix
Using values of atomic weights
obtained by Stanislao Cannizzaro in
1858, de Chancourtois devised a
spiral graph that was arranged on a
cylinder which he called vis
tellurique, or telluric helix because
tellurium was the element in the
middle of the graph.
The surface of the cylinder had a circumference
of 16 units, the approximate atomic weight of
oxygen, and the resulting helical curve, which de
Chancourtois called a square cirlcl triangle,
brought similar elements onto corresponding
points above or below one another on the
cylinder. Thus, he suggested that "the properties
of the elements are the properties of numbers.”
13. De Chancourtois was the first scientist to see the periodicity of elements
when they were arranged in order of their atomic weights. He saw that the
similar elements occurred at regular atomic weight intervals.
14. John A. R. Newlands (1837-1898)
Law of Octaves
• From 1863 through 1866, Newlands published
papers on the relationships between the
elements. In 1865 he stated:
“If the elements are arranged in the order of their
equivalents, with a few slight transpositions, as in
the accompanying table, it will be observed that
elements belonging to the same group usually
appear on the same horizontal line.”
15. Newlands continued:
“It will also be seen that the numbers of analogous elements
generally differ either by 7 or by some multiple of seven; in
other words, members of the same group stand to each
other in the same relation as the extremities of one or more
octaves in music. Thus, in the nitrogen group, between
nitrogen and phosphorus there are 7 elements; between
phosphorus and arsenic, 14; between arsenic and antimony,
14; and lastly, between antimony and bismuth, 14 also.
This peculiar relationship I propose to provisionally term the
"Law of Octaves".
The complete text of all Newlands’ papers can be found in his book The Periodic
Law (1884), at http://www.chymist.com/The Periodic Law.pdf
16. Dmitri Mendeleev (1834-1907)
The Periodic Law, 1869
“I began to look about and write down the elements
with their atomic weights and typical properties,
analogous elements and like atomic weights on
separate cards, and this soon convinced me that the
properties of elements are in periodic dependence
upon their atomic weights.”
--Mendeleev, Principles of Chemistry, 1905, Vol. II
The problem with previous attempts to organize the
elements was that the pattern of repeating
properties did not hold after the element calcium.
Mendeleev proposed longer columns of elements to
allow him to align those elements with similar
properties
Right: Mendeleev’s first sketch of his periodic table
An interesting story relating Mendeleev’s solution to the periodic
classification can be found at http://www.chymist.com/Music of
New Spheres.pdf
17. • Mendeleev’s arrangement of the elements were presented to the Russian
Physico-chemical Society by Professor Menschutkin because Mendeleev was ill.
• The table was first published in the German chemistry periodical, Zeitschrift fϋr
Chemie, in 1869.
18. Translation of the German text in Zeitschrift fϋr Chemie, 1869:
Concerning the relation between the properties and atomic
weights of elements. By D. Mendeleev.
Arranging the elements in vertical columns with increasing
atomic weights, so that the horizontal rows contain similar
elements, again in increasing weight order, the following table
is obtained from which general predictions can be drawn.
Elements show a periodicity of properties if listed in order of
size of atomic weights. Elements with similar properties either
have atomic weights that are about the same (Pt, Ir, Os) or
increase regularly (K, Rb, Cs). The arrangement of the elements
corresponds to their valency, and somewhat according to their
chemical properties (eg Li, Be, B, C, N, O, F). The commonest
elements have small atomic weights.
1. The value of the atomic weight determines the character of the element.
2. There are unknown elements to discover eg., elements similar to Al and Si
with atomic weights in range 65-75.
3. The atomic weights of some elements may be changed from knowing the
properties of neighbouring elements. Thus the atomic weight of Te must be in
range 123-126. It cannot be 128.
4. Some typical properties of an element can be predicted from its atomic
weight.
19. Mendeleev published a revised, horizontal table in 1871
Note the structure of this table.
It was clear, that there were a number of gaps of “missing” elements in the table.
Mendeleev, made several predictions about properties of some missing elements.
20. Mendeleev predicted four elements: ekaboron (Eb), ekaaluminium (El), ekamanganese (Em),
and ekasilicon (Es)
Ekaboron and scandium
Scandium was isolated as the oxide in autumn, 1879, by Lars Fredrick Nilson.
Per Teodor Cleve recognized the correspondence and notified Mendeleev late in that year.
Mendeleev had predicted an atomic mass of 44 for ekaboron in 1871 while scandium has an
atomic mass of 44.955910.
21. Ekaaluminium and gallium
In 1871 Mendeleev predicted the existence of yet undiscovered element he
named eka-aluminum (because of its proximity to aluminum in the periodic table).
The table below compares the qualities of the element predicted by Mendeleev
with actual characteristics of Gallium, discovered by Lecoq de Boisbaudran in
1875).
22. Ekasilicon and germanium
Germanium was isolated in 1882 by Clemens Alexander Winkler,
and provided the best confirmation of the theory up to that time,
due to its contrasting more clearly with its neighboring elements
than the two previously confirmed predictions of Mendeleev do
with theirs.
23. Ekamanganese and technetium
Technetium was isolated by Carlo Perrier and Emilio Segrè in 1937, well
after Mendeleev’s lifetime, from samples of molybdenum that had been
bombarded with deuterium nuclei in a cyclotron by Ernest Lawrence.
Mendeleev had predicted an atomic mass of 100 for ekamanganese in
1871 and the most stable isotope of technetium is 98Tc.
24. Julius Lothar Meyer (1830-1895)
In 1864, Meyer produced a table of 28 elements
which he listed by their valence or ‘combining
power’ of the elements (now called oxidation
number).
The 28 elements were almost entirely main
group elements.
He incorporated what we now call transition
metals in another table in 1868 which listed the
elements in increasing weight order with
elements with the same valence in a given
column.
Meyer's table was not published until 1870.
25.
26. • Also, in 1870, Lothar Meyer plotted atomic volumes against
atomic weight.
• Meyer measured the volume of one atomic weight's worth of
each element (i.e., one mole) and figured that since the number
of atoms in each amount was the same, the volumes measured
must represent the relative volumes of the individual atoms.
27. Lewis Reeve Gibbes (1810-1894)
Professor of Chemistry at the College of Charleston
from 1839 to 1892
Between 1870 and 1874 Gibbes, without knowing
any of the work by Newlands, Mendeleev and Meyer,
worked out the first version of his "Synoptical Table
of the Chemical Elements“ and in October, 1875,
discussed an improved form of it at a meeting of the
Elliott Society of Charleston
http://www.chymist.com/Lewis Reeve Gibbes.pdf
28. The Nobel Gases
In 1785 , Henry Cavendish reported on his analysis of air (Philosophical
Transactions 75, 372 (1785):
…after which only a small bubble of air remained unabsorbed, which certainly was not
more than 1/120 of the bulk of the phlogisticated air let up into the tube; so that if
there is any part of the phlogisticated air of our atmosphere which differs from the
rest, and cannot be reduced to nitrous acid, we may safely conclude, that it is not
more than 1/120 part of the whole.
In 1894, Lord Rayleigh (John Strut) (1842-1919) and William Ramsey (1852-
1916) jointly announced the discovery of argon, both working on
properties of atmospheric nitrogen.
On August 18, 1868 French astronomer Pierre Janssen observed a bright yellow
line with a wavelength of 587.49 nanometers in the spectrum of the
chromosphere of the Sun during a total solar eclipse
On October 20, 1868, English astronomer Norman Lockyer also observed a
yellow line in the solar spectrum, which he concluded that it was caused
by an element in the Sun unknown on Earth. Lockyer and English chemist
Edward Frankland named the element with the Greek word for the Sun,
ἥλιος (helios).
On March 26, 1895 Sir William Ramsay isolated helium on Earth by treating the
mineral cleveite (a variety of uraninite) with mineral acids.
Cavendish
Rayleigh
Ramsay
29. Henry Moseley (1887-1915)
In 1913, using x-ray
diffraction spectra,
Moseley showed a
systematic relation
between wavelength
and atomic number
Resulted in
arrangement of the
periodic table by
atomic number
rather than atomic
weight
32. Glenn Seaborg (1912-1999)
• Starting in 1940, Seaborg was the principal or co-
discoverer of ten elements: plutonium (94),
americium (95), curium (96), berkelium (97),
californium (98), einsteinium (99), fermium (100),
mendelevium (101), nobelium (102) and element
106, which was later named seaborgium in his
honor. He also developed more than 100 atomic
isotopes, and is credited with important
contributions to the separation of the isotope of
uranium used in the atomic bomb at Hiroshima.
• Seaborg reconfigured the periodic table by placing
the lanthanide/actinide series at the bottom of the
table.
• Seaborg also proposed extending the periodic table
to include predicted elements up to atomic number
168.
http://www.chymist.com/Extending the Periodic Table.pdf