Ppt on history of atom models

The Structure & Stability of Atoms. Early Atomic History There have been many different theories, reflecting different times and cultures, to explain.

yet know the formulas for either compound, nor was the concept of atoms fully developed. Consider the compounds of water and hydrogen peroxide. At this point in history, chemists knew the compounds were different, and that they both contain/and this is the source of the cathode rays. Early Atomic Models One of the key features of Thomson’s atomic model is that most of the atomic mass and all of the positive charge is uniformly distributed throughout the atom. Early Atomic Models Thomson had a graduate /


ICP 9/10/12 Atom and the History of the Atom. Warmup 1.What is an atom? 2.What are the parts of an atom? 3.Draw what an atom looks like.

ICP 9/10/12 Atom and the History of the Atom Warmup 1.What is an atom? 2.What are the parts of an atom? 3.Draw what an atom looks like. The History of the Atom We are going to look at how our understanding of the atom developed. The History of the Atomic Model Democritus A Greek philosopher in the year 400BC. He used the word Atomos to describe the smallest possible piece of matter. Democritus Just/


History of the Atom Model 450 BC Democritus (Greek)- World was made of 2 things: 1.Empty space 2.Tiny particles call atoms (Atomus= indivisible) Aristotle.

evidence. Air, earth, fire & water History of the Atom Model Antonine Lavoisier (French)- 1782 Law of Conservation of Matter (mass) Matter is neither created Nor destroyed, it is only rearranged. Mass of reactants = Mass of products History of the Atom Model Joseph Proust (French)- 1799 Law of Definite Proportions Atoms must combine in whole number ratios. H 2 0 vs H0 ½ History of the Atom Model Joseph Proust (French)- 1799 Law of Multiple Proportions Atoms can combine in different whole/


Evolution of the ATOM Project Create a foldable discussing the evolution of the atom starting with Democritis and ending with the Electron Cloud Model.

GOLD ARISTOTLE WINS!!! Democritus’ idea ofatoms” was ignored and forgotten for more than 2000 years! HISTORY OF THE ATOM 1808 John Dalton (England) All matter is made up of tiny spheres called … ATOMS Dalton combines the idea of elements with that of atoms! Dalton’s Atomic Theory Billiard Ball Model 1.All elements are composed of atoms. –indivisible and indestructible 2.Atoms of the same element are alike 3.Atoms of different elements are different 4.Chemical/


S.MORRIS 2006. Papercuts This piece of paper is 28cm x 2.5 cm How many times would you have to cut this piece of paper to be the same width as an atom?

meter 1 millimeter = 1 000 000 000 picometers That’s teeny tiny ! Who are these dead dudes? How did they contribute to our present day model of an atom? HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms he pounded up materials in his pestle and mortar until he had reduced them to smaller and smaller particles which he called ATOMA (greek for indivisible) This/


Investigating Atoms and Atomic Theory HISTORY OF THE ATOM AND ATOMIC THEORY.

Investigating Atoms and Atomic Theory HISTORY OF THE ATOM AND ATOMIC THEORY Atomos: Not to Be Cut Atomic Models This model of the atom may look familiar to you. This is the Bohr model. In this model, the nucleus is orbited by electrons, which are in different energy levels. This model of the atom may look familiar to you. This is the Bohr model. In this model, the nucleus is orbited by electrons, which are in different energy levels/


Atomic Structure GChem Chapter 3. Learning objectives 1.Discuss the history of the current atomic model, including contributions of: Dalton, Thomson,

objectives 1.Discuss the history of the current atomic model, including contributions of: Dalton, Thomson, Rutherford, Moseley, Bohr. 2.Explain the laws of conservation of mass, definite proportions, and multiple proportions. 3.Describe the location, mass and charge of the three components of an atom. 4.Explain and calculate the atomic mass, atomic number and charge for any given atom. 5.Explain the concept of isotopes and calculate the average atomic mass for an element/


A History of Atomic Theory AndStructure. History of the Atom Not the history of atom, but the idea of Original idea began Ancient Greece (400 B.C.E.)

A History of Atomic Theory AndStructure History of the Atom Not the history of atom, but the idea of Original idea began Ancient Greece (400 B.C.E.) Democritus - Greek philosopher (460-370 BC) Worked with his mentor Leucippus to develop first atomic theory. History of Atom Felt that had to be the smallest piece making up everything For example: If you look at the beach...made of sand Couldn’t you cut the sand into/


Atoms & Elements The building blocks of matter. Early Atomic History There have been many different theories, reflecting different times and cultures,

yet know the formulas for either compound, nor was the concept of atoms fully developed. Consider the compounds of water and hydrogen peroxide. At this point in history, chemists knew the compounds were different, and that they both contain/and this is the source of the cathode rays. Early Atomic Models One of the key features of Thomson’s atomic model is that most of the atomic mass and all of the positive charge is uniformly distributed throughout the atom. Early Atomic Models Thomson had a graduate /


Atoms What are we going to study about the atom? History Structure Properties Forces.

are we going to study about the atom? History Structure Properties Forces Isotopes What is an isotope? Atoms of the same element that have different number of neutrons. Also have different number of neutrons. Common Isotopes of Carbon C-12 C-13 # of p+, n 0, e-? Atomic Structure History, Structure and Properties of the Atom History of the Atom Great Thinkers (2,000yrs. Ago) Age of Reason and Thought Democritus vs. Aristotle view on the/


Atoms & Elements The building blocks of matter. Early Atomic History There have been many different theories, reflecting different times and cultures,

nor was the concept of atoms fully developed. Consider the compounds of water and hydrogen peroxide. At this point in history, chemists knew the/of the cathode rays. Early Atomic Models One of the key features of Thomson’s atomic model is that most of the atomic mass and all of the positive charge is uniformly distributed throughout the atom. Early Atomic Models Thomson had a graduate student, Ernest Rutherford. In 1911, Rutherford, Geiger and Marsden performed an experiment to confirm Thomson’s atomic model/


Particles, Nuclei, and Isotopes The Nuts and Bolts of Chemistry.

, and Isotopes The Nuts and Bolts of Chemistry Atomic History: An Overview Early Greeks - Democritus vs Aristotle Dalton’s Atomic Theory Thomson - discovery of electrons Rutherford - discovery of nucleus Chadwick - discovery of neutron Bohr - planetary model of atom Atomic History: An Overview Early Greeks - Democritus vs. Aristotle Dalton’s Atomic Theory Thomson - discovery of electrons Rutherford - discovery of nucleus Chadwick - discovery of neutron Bohr - planetary model of atom Early Greeks What is the/


Atomic Structure Unit 2.

. The Greeks History of the Atom Not the history of atom, but the idea of the atom In 400 B.C the Greeks tried to understand matter (chemicals) and broke them down into earth, wind, fire, and air. Democritus and Leucippus Greek philosophers   Greek Model Greek philosopher Idea of ‘democracy’ Idea of ‘atomos’ –Atomos = ‘indivisible’ –‘Atom’ is derived No experiments to support idea Continuous vs. discontinuous theory of matter Democritus’s model of atom No protons/


HISTORY OF THE ATOM 1910 Ernest Rutherford He oversaw his students, Geiger and Marsden, carrying out his famous Gold Foil experiment. They fired alpha.

Niels Bohr Bohr studied under Rutherford at Victoria University in Manchester. Bohr proposed a new model of the hydrogen atom. This model retained Rutherford’s nucleus but did not allow the electrons to move anywhere within the volume of space around the nucleus. HISTORY OF THE ATOM The Bohr Atomic Model of the Hydrogen Atom Rutherford’s planetary model is correct. When an electron is in an "allowed" orbit it does not radiate/


HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms He pounded up materials in his pestle and mortar until he had reduced them to smaller.

smaller particles which he called ATOMOS (greek for indivisible) HISTORY OF THE ATOM SCIENTISTMODEL OF THE ATOM MAJOR CONTRIBUTIONS & POINTS DALTON (1803) AKA: Billard Ball model Matter is made of small particles called atoms. 1. Atoms are indestructible. They cannot be created or destroyed during chemical or physical changes. 2.Atoms of an element are identical. They have the same mass. 3.Atoms of different elements have different masses. 4.Compounds are formed/


A Brief History of the Modern Atomic Model 1803 - 1950’s Pgs 102-114, Chemistry Matter and Change.

, but we can determine the probability that they are in a given space (around the nucleus). We cannot see atoms, but math shows this is the “best” model we have. History of Atom History Book Project (20 pts) You must have one page for each development of the atomic model. On each page you must include: 1.An image or drawing that shows an important part 2.A sentence/


Chapter 4.1 An Atomic Model of Matter The Greek Model The Greek Model Dalton’s model Dalton’s model Thompson’s model Thompson’s model Rutherford’s model.

. They are like bees around a hive. History Timeline of the Atom History Timeline of the Atom History Timeline of the Atom History Timeline of the Atom Building blocks of molecules Atoms are the smallest part of an element that acts like that element Atoms are the smallest part of an element that acts like that element Atoms are composed of 3 smaller particles: Protons, electrons and neutrons. Atoms are composed of 3 smaller particles: Protons, electrons and neutrons. Modern Modern Model of Atom


The Atom Chapter 4 I. History of the Atomic Theory IV. Mass of Atoms A. Democritus A. Atomic Mass B. Aristotle B. Average Atomic Mass C. Lavoisier C.

-24 g –e - = 9.11 x 10 -28 g –The charges balance! But, But, –How are the electrons arranged? –There is still mass that is unaccounted for II. History of the Atomic Structure Rutherford Model of the Atom Electrons orbit nucleus in predictable paths D. Niels Bohr (1913) In 1935 In 1935 1. Discovers neutron in nucleus 2. Neutron is neutral - does not have a charge/


Atomic Theory Model History and Structure. I. Models of the Atom A. The Evolution of Atomic Models 1. He believed that there had to be a basic building.

Atomic Theory Model History and Structure I. Models of the Atom A. The Evolution of Atomic Models 1. He believed that there had to be a basic building block that made up all other matter. 2. Democritus believed the atom was it – smallest particle of matter. a. All matter consists of invisible particles called atoms. b. Atoms are indestructible. c. Atoms are solid but invisible. d. Atoms are homogenous. e. Atoms differ in size, shape, mass, position, and/


HAVE A GOOD LOOK ATOM ROUND ABOUT NUMBERIFFICSUPER SMALL ATOMIC POWER -BONUS- 161116*21 271217*22 381318*23 491419*24 5101520*25 Copyright © 2010 Ryan.

model of the atom, and which represents the early J.J. Thompson model? Copyright © 2010 Ryan P. Murphy Please name A, B, C, and D? –And name the atom? Copyright © 2010 Ryan P. Murphy The nucleus of the atom is… Copyright © 2010 Ryan P. Murphy The nucleus of the atom/Human Evolution Lesson Bundle Life Origins and Human Evolution Quiz Game Geologic Timescale, Earth System History Lesson Bundle Earth Geologic History Quiz Game Life Origins and Human Evolution Quiz Game Life Origins, Miller Urey Experiment /


Michael Seeds Dana Backman Chapter 8 Origin of the Solar System and Extrasolar Planets.

atoms, such as hydrogen, to make heavier atoms. The History of the Atoms in Your Body Generation of stars cooked the original particles, fusing them into atoms such as carbon, nitrogen, and oxygen. Those are common atoms in your body. Even the calcium atoms in your bones were assembled inside stars. The History of the Atoms in Your Body Most of/. The creation of a planetary atmosphere from a planet’s interior is called outgassing. Growth of Protoplanets Models of the formation of Earth indicate that/


History of the Atom Activity. Objectives: – Today I will be able to: Explore the nature of science by completing an activity Research a scientist to understand.

Share information with the group Construct a timeline of for the history of the atom Project Format Name of Scientist Their Accomplishment – Regarding the atom – Development of the atom Date of discovery Picture of the experiment (if there is an experiment) – – Explain what they found in their experiment Picture of the model of the atom constructed (if there is a picture available) – What is the model of the atom showing? Include APA citations for the sources used/


The theory of concurrent programming for a seasoned programmer © Roman Elizarov, Devexperts, 2012.

atomic registers -Atomic (linearizable) registers work as if each write or read is instantaneous and as if there is no parallelism -Will define what this means precisely later A more general model of execution is needed to analyze a wider class of primitives Lamport’s happens before (occurs before) model An execution history is a pair (H, → H ) -“H” is a set of/ Memory (STM) Is a simplified programming model -Similar to locks, but use atomic section instead of synchronized -Same problems as locks, but /


HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms he pounded up materials in his pestle and mortar until he had reduced them to smaller.

sometimes eject a far smaller negative particle which he called an ELECTRON HISTORY OF THE ATOM Thompson develops the idea that an atom was made up of electrons scattered unevenly within an elastic sphere surrounded by a soup of positive charge to balance the electrons charge 1904 like plums surrounded by pudding. PLUM PUDDING MODEL HISTORY OF THE ATOM 1910 Ernest Rutherford oversaw Geiger and Marsden carrying out his famous/


History of the atom: History of the atom: Changing atomic models.

History of the atom: History of the atom: Changing atomic models MODELS A VISUAL, VERBAL, OR MATHEMATEICAL EXPLANATION OF HOW PHENOMENA OCCUR OR HOW DATA AND EVENTS ARE RELATED. MODELS HELP TO EXPLAIN THE STRUCTURE OF ATOMS BECAUSE THEY ARE TOO SMALL TO SEE. Democritus (400 B.C. / Greece) Proposed that matter was composed of tiny indivisible particles he called “atom” Not based on experimental data In Greek: atomos means “indivisible” Greek Model of Atom (Democritus) Aristotle (384 B/


Chapter 2 Atoms, Molecules, and Ions. Section 2.1 The Early History of Chemistry Copyright © Cengage Learning. All rights reserved 2  Greeks were the.

to Characterize the Atom Electron Cloud Model  Refined Bohr’s model  Electron Cloud- visual model of most likely locations of an electron  Electron cloud model explains location of electrons  Example- fan blades- cannot see individual blades when in motion  Makes atom look like sphere under scanning tunneling microscope Section 2.4 Early Experiments to Characterize the Atom Electron Cloud Model Section 2.4 Early Experiments to Characterize the Atom History of Atomic Chemistry Section 2/


Introduction to the Periodic Table. History of Periodic Table Basic chemical elements known since prehistoric times Easy to mine with simple tools. Gold.

P. History of Periodic Table urine Hennig Brand (and later Robert Boyle) turned urine into P! Ewww ! History of Periodic Table Elements Song 1 Scientists have identified 90 naturally occurring elements, and created about 28 others (present total 118). History of Periodic Table/energy levels – lowest energy level nearest to nucleus. 1 st energy level 2nd energy level Subatomic Structure and Bohr Model of Atom Li 3 7 1 outer electron in 2nd electron shell 2 electrons (max.) in 1 st electron shell Electron /


History of the Development of the Atomic Model, Part 1 AS Aim #1 Where did the idea of the atom come from?

History of the Development of the Atomic Model, Part 1 AS Aim #1 Where did the idea of the atom come from? Atomic Model of the Atom Models help us describe several things about an atom: –____________ – what its made of –__________________ – lets us determine how atoms interact with each other We will look at several models of the atom that build upon previous models The modern model of the atom is based on the work of many scientists, not just one! Early Greek/


Atomic Structure Chemistry: Chapter 4. AtomsBuilding block of matter Cannot be seen Known to exist through indirect evidence. Gathering information w/o.

actually seeing or touching the object. Used to develop a mental picture or model. Ex. gravity History of the atom overview  http://www.nobeliefs.com/atom.htm http://www.nobeliefs.com/atom.htm http://www.chalkbored.com/lessons/chemistry-11/atomic-models-handout.pdf Greek Model 2400 years ago, Greek philosopher Democritus 1st to use the term “atom” meaning “indivisible” or “not to be cut” Ancient Greeks believed matter was/


HISTORY OF ATOMS. What is an atom? An atom, in the simplest model, consists of a nucleus and orbiting electrons. There are only about 100 different kinds.

HISTORY OF ATOMS What is an atom? An atom, in the simplest model, consists of a nucleus and orbiting electrons. There are only about 100 different kinds of atoms in the entire universe. Everything we see is made up of these 100 atoms in an unlimited number of combinations. How these atoms are arranged and bonded together determines whether the atoms make up a cup of water, a piece of metal, or the fizz that comes out/


HISTORY OF THE ATOM 460 BC Democritus develops the idea of atoms He got the idea that everything was made of small bits by looking at sand on the beach.

, identical and negatively charged particles which were later called ELECTRONS HISTORY OF THE ATOM Thomson developed the idea that atoms were made up of electrons scattered unevenly in a soup of positive charge to balance the electrons negative charge. 1904 Thomson creates a new model of the atom. like plums surrounded by pudding. PLUM PUDDING MODEL HISTORY OF THE ATOM 1910 Ernest Rutherford discovers the nucleus His team fired alpha particles at a/


History of Atoms Notes Use the information on each slide to fill in the blanks on the student notes.

) Round, Solid Atom History of Atoms John Dalton The Atomic Theory John Dalton was an English Scientist. In 1803 he proposed the atomic theory that says: -Atoms cannot be divided -Atoms are invisible -All elements are made of atoms -Atoms of the same element are the same -Atoms of different elements are different -Molecules are formed by two or more atoms joined together Round, Solid Atom Billiard Ball Model History of Atoms Joseph J. Thomson What are atoms made of? In 1897/


Atomos: Not to Be Cut The History of Atomic Theory.

Be Cut The History of Atomic Theory What do Dinosaurs and Atoms have in Common? (not in notes) No one has seen an atom or a dinosaur directly. We know of their existence only by indirect evidence. Our theories of both dinosaurs and atoms has changed over time based on this indirect evidence Atomic Models This model of the atom may look familiar to you. This is the Bohr model. In this model, the nucleus/


History of the Atom. The Atom…a Working Model The history of the atom has shown that through the years, the model has needed to be modified to reflect.

a certain amount of energy to orbit the atom. This will prevent the atom from getting sucked into the nucleus. Shortcomings to Bohr’s Model Unfortunately, Bohr was unable to expand his model to other atoms besides Hydrogen. He could explain the activity of the single electron in a hydrogen atom but not for atoms with more than one electron. Summary of History Our ideas about the nature of atoms have progressed over/


The Greeks History of the Atom Not the history of atom, but the idea of the atom In 400 B.C the Greeks tried to understand matter (chemicals) and broke.

The Greeks History of the Atom Not the history of atom, but the idea of the atom In 400 B.C the Greeks tried to understand matter (chemicals) and broke them down into earth, wind, fire, and air. Democritus and Leucippus Greek philosophers FireWater Earth Air ~ ~ Greek Model Greek philosopher Idea of ‘democracy’ Idea of ‘atomos’ –Atomos = ‘indivisible’ –‘Atom’ is derived No experiments to support idea Democritus’s model of atom No protons, electrons, or neutrons/


S. Aldrich 2008. HISTORY OF THE ATOM 460 BCE Democritus develops the idea of atoms He believed that you could cut objects in half, over and over again,

were in orbits traveling around the nucleus in definite paths- with each orbit only able to contain a certain number of electrons. Bohr’s Atom electrons in orbits nucleus HISTORY OF THE ATOM 1924 Erwin Schrodinger He developed the Electron Cloud model, proposing that the exact path of electrons cannot be predicted. He believed that the electron cloud was the area where electrons were likely to be/


Atomic Structure Chemistry The Greeks History of the Atom Not the history of atom, but the idea of the atom In 400 B.C the Greeks tried to understand.

History of the Atom Not the history of atom, but the idea of the atom In 400 B.C the Greeks tried to understand matter (chemicals) and broke them down into earth, wind, fire, and air. Democritus and Leucippus Greek philosophers   The Hellenic Market FireWater Earth Air ~ ~ ~400 BCDemocritus First suggested the existence of atoms. Name atom - atomos All matter is made up of small indestructible particles called atoms DEMOCRITUS (400 BC) – First Atomic/


History of the Atom Chapter 4. The Atom… a Working Model The history of the atom has shown that through the years, the model had needed to be modified.

History of the Atom Chapter 4 The Atom… a Working Model The history of the atom has shown that through the years, the model had needed to be modified to reflect the discoveries that scientists have made. It’s important to know who the main contributors are to this “working modelof the atom and what their shortcomings were that were then modified. John Dalton Ancient Greeks had ideas about particles and atoms as/


The History of Chemistry Eleven big ideas Chemistry Mr. Bimber.

wave. His equations predict dual behavior of everyting, from protons to planets. Chemistry History: Democritus : atom Democritus : atom Dalton: 5 part atomic theory Dalton: 5 part atomic theory Mendeleev &/or Moseley: periodic table Mendeleev &/or Moseley: periodic table Thomson: Plum Pudding theory/electrons Thomson: Plum Pudding theory/electrons Rutherford: Nucleus Rutherford: Nucleus Bohr: Mechanical Quantum Mech. Model Bohr: Mechanical Quantum Mech. Model Planck: Quantum Theory Planck: Quantum Theory/


On Knowing.

our lifetimes compare to the age of the universe? The Cosmic Calendar: a scale on which we compress the 13.7 billion year history of the universe into 1 year. This is a time scale model that used a scale factor of 14,000,000,000:1. / Arrow of Time Sentient Life Lots of Atoms Single Atoms No Arrow of Time The early universe expanded much faster than the speed of light, so there are objects and large regions of space we have never seen. Size The Universe Speed of Light Time This violates no law of physics /


Chapter 3 Atomic Structure

.J. Thompson’s Model Cathode rays are beams of negatively-charged particles called electrons. All atoms contain electrons. Atoms also contain an equal and opposite positive charge. Ernest Rutherford 1871-1937 "All science is either physics or stamp collecting." Rutherford, Ernest (1871-1937): Born in New Zealand, Rutherford studied under J. J. Thomson His work constituted a notable landmark in the history of atomic research as he/


History of the Atom.

History of the Atom History of the atom Not the history of atom, but the idea of the atom. Original idea Ancient Greece (400 B.C.) Democritus - Greek philosopher. History of Atom Looked at beach Made of sand Cut sand - smaller sand Smallest possible piece? Atomos - not to be cut Another Greek Aristotle - Famous philosopher All substances are made of 4 elements Fire - Hot Air - light Earth - cool, heavy Water - wet Blend these in different proportions to/


ATOMIC STRUCTURE. Objectives: SWBAT Identify three subatomic particles and compare their properties. Distinguish the atomic number of an element from.

oil drop experiment HISTORY OF THE ATOM 1910 Ernest Rutherford oversaw Geiger and Marsden carrying out his famous experiment. They fired Helium nuclei at a piece of gold foil which was only a few atoms thick. They found that although most of them passed through. About 1 in 10,000 hit. Rutherford’s experiment. Plum Pudding model of an atom. Results of foil experiment if Plum Pudding model had been correct/


BELL RINGER What are the three subatomic particles? (Things smaller than an atom, you learned in 8 th grade)

atom, you learned in 8 th grade) History of the Atom Where it all began… The atom starts not with the ________ of the atom, but the ______ of the atom. More than ______ years ago, (around ____ BC) Greek philosophers, ___________ and ____________ debated the nature of the universe. history/ Thomson’s work. 1910 Ernest Rutherford He believed the plum pudding model was correct, but wanted to discover the _____ of atoms. size Rutherford’s experiment The radioactive material released ______ particles, which/


Modern Philosophy since the Pre-Enlightenment

the Manchester School in America until today, with no history of feudalism or state church was opposed by Romanticism & nativism// consistency criterion of truth: The broader the scope of a consistent model, the truer. The broader the scope of a consistent model that a /of position (m) & momentum (p) of a sub-atomic particle: (Dm)(Dp) ³ h , and the sensitivity of the observer’s measurement of one of these to his own action of measuring the other (if the measurement of one is precise, the measurement of/


Models of the Atom in History

Models of the Atom in History OB: students will review the models of the atom through scientific history, learning how ideas progressed and were dismissed as new information was developed. Most famous chemists had remarkable mustaches. That’s the easiest way to keep track of who’s who in science! The first of many mustaches in our course! About 2400 years ago a philosopher named Democritus came up with this idea/


5 years 14 years 20 years 28 years 50 years

in order to minimize potential damage from ground shaking during an earthquake? Steel Stucco Masonry Unreinforced Concrete Adobe The sedimentary rocks immediately below and above an angular unconformity record a history of: Erosion-folding-deposition-erosion Folding-erosion-deposition-folding Deposition-erosion-deposition-folding Erosion-deposition-folding-erosion Deposition-folding-erosion-deposition The sedimentary rocks immediately below and above an angular unconformity/


History of the Atom From Atomism to the Nuclear Model Jack F. Eichler Department of Chemistry University of California, Riverside.

History of the Atom From Atomism to the Nuclear Model Jack F. Eichler Department of Chemistry University of California, Riverside 1. Where did the idea of atoms originate? 2.What is the evidence that allows us to conclude that atoms exist? 3.How have our models of the atom evolved over time? Let’s take a tour through a history of scientific discovery and find answers to these questions… 2 Democritus – Atomism (5th Century BCE) 3 Readings/


ATOMIC STRUCTURE AND HISTORY

his theory, but they revised it. John Dalton (born 1766) HISTORY OF THE ATOM Investigations in the 1800’s proved that atoms were in fact divisible. ATOM- smallest particle of an element that retains the chemical properties of that element. Thomson’s Model of the Atom Joseph John Thomson 1898 Thompson’s experiments provided the first evidence that atoms are made of even smaller particles. Experiments using electric currents were carried out/


Atom Notes Atom – small particle that makes up most types of matter (One million atoms lined up equals the thickness of one human hair) Atomic structure.

atoms lined up equals the thickness of one human hair) Atomic structure Nucleus – central part of an atom Protons – positively charged particles in the nucleus of an atom Neutrons – uncharged particles in the nucleus of an atom Electrons - negatively charged particles in an atom Atom History of Atomic Theory Dalton – (atomic model) Theory that substances were made of atoms, small, hard, dense spheres that could not be created, destroyed, or altered. Dalton’s model of the atom John Dalton History of Atomic/


Ads by Google