Chapter 2. Atoms and Ions

Size: px
Start display at page:

Download "Chapter 2. Atoms and Ions"

Transcription

1 Chapter 2 Atoms and Ions

2 A History of Atomic Models 400 B.C.E. (Democritus, a early atomist) 1804 (Dalton)

3 Law of Conservation of Mass Antoine Lavoisier In a chemical reaction, matter is neither created nor destroyed. Total mass of the materials you have before the reaction must equal the total mass of the materials you have at the end. total mass of reactants = total mass of products

4 Law of Conservation of Mass 7.7 g Na g Cl g NaCl

5 Law of Definite Proportions Joseph Proust All samples of a given compound, regardless of their source or how they were prepared, have the same proportions of their constituent elements.

6 Proportions of Na and Cl in Sodium Chloride A g sample of sodium chloride contains 39.3 g of sodium and 60.7 g of chlorine A g sample of sodium chloride contains 78.6 g of sodium and g of chlorine A g sample of sodium chloride contains g of sodium and g of chlorine

7 Law of Multiple Proportions John Dalton When two elements (call them A and B) form two different compounds, the masses of B that combine with 1 g of A can be expressed as a ratio of small, whole numbers.

8 Law of Multiple Proportions Carbon monoxide contains 1.33 g of oxygen for every 1.00 g of carbon. Carbon dioxide contains 2.67 g of oxygen for every 1.00 g of carbon. 1.33/1.00 = 4/3 2.67/1.00 = 8/3

9 Dalton s Atomic Theory 1. Each element is composed of tiny, indestructible particles called atoms. 2. All atoms of a given element have the same mass and other properties that distinguish them from atoms of other elements. 3. Atoms combine in simple, whole-number ratios to form molecules of compounds. 4. In a chemical reaction, atoms are reorganized in the way they are bound together. 5. Atoms of one element cannot change into atoms of another element.

10 Some Notes on Charge Two kinds of charge called + and Opposite charges attract + attracted to Like charges repel + repels + repels To be neutral, something must have no charge or equal amounts of opposite charges

11 J.J. Thomson and Cathode Rays Cathode (-) (+) Power Supply Examined the electrically charge particles in cathode rays Measured the amount of force necessary to deflect the paths of the particles The particles have a negative charge. The amount of deflection was related to two factors, the charge and mass of the particles. Every material tested contained these same particles.

12 Thomson s Conclusions If the particle has the same amount of charge as a hydrogen ion, then it must have a mass almost 2000 x smaller than hydrogen atoms! The only way for this to be true is if these particles were pieces of atoms. Apparently, the atom is not unbreakable. Thomson believed that these particles were the ultimate building blocks of matter. These cathode ray particles became known as electrons.

13 A New Theory of the Atom Thomson proposed that instead of being a hard, marblelike unbreakable sphere, the way Dalton described it, the atom actually had an inner structure. The structure of the atom contains many negatively charged electrons. These electrons are held in the atom by their attraction for a positively charged electric field within the atom.

14 A History of Atomic Models 400 B.C.E. (Democritus, a early atomist) 1804 (Dalton) 1903 (Thomson)

15 Predictions of the Plum Pudding Atom The mass of the atom is due to the mass of the electrons within it. Electrons are the only particles in Plum Pudding atoms, therefore the only source of mass. The atom is mostly empty space and should not have a bunch of negatively charged particles near each other as they would repel.

16 Radioactivity In the late 1800s, Henri Becquerel and Marie Curie discovered that certain elements would constantly emit small, energetic particles and rays. These energetic particles could penetrate matter. Ernest Rutherford discovered that there were three different kinds of emissions: alpha rays made of particles with a mass 4 x H atom and + charge beta rays made of particles with a mass ~1/2000 th H atom and charge gamma rays that are energy rays, not particles

17 Explaining Results of α-particle Scattering Experiments Actual Result Rutherford s expectation Small, positively charged α-particles should pass through the nebulous, positively charged cloud of the Thomson atomic model largely undeflected. Some would be slightly deflected by passing near electrons (present to neutralize the positive charge of the cloud).

18

19 To minimize alpha loss by scattering from air molecules, the experiment was carried out in a fairly good vacuum, the metal box being evacuated through a tube T (see below). The alphas came from a few milligrams of radium (to be precise, its decay product radon 222) at R in the figure below, from the original paper, which goes on: "By means of a diaphragm placed at D, a pencil of alpha particles was directed normally on to the scattering foil F. By rotating the microscope [M] the alpha particles scattered in different directions could be observed on the screen S." Actually, this was more difficult than it sounds. A single alpha caused a slight fluorescence on the zinc sulphide screen S at the end of the microscope. This could only be reliably seen by dark-adapted eyes (after half an hour in complete darkness) and one person could only count the flashes accurately for one minute before needing a break, and counts above 90 per minute were too fast for reliability. The experiment accumulated data from hundreds of thousands of flashes.

20 Rutherford's partner in the initial phase of this work was Hans Geiger, who later developed the Geiger counter to detect and count fast particles. Many hours of staring at the tiny zinc sulphide screen in the dark must have focused his mind on finding a better way! In 1909, an undergraduate, Ernest Marsden, was being trained by Geiger. To quote Rutherford (a lecture he gave much later): "I had observed the scattering of alpha-particles, and Dr. Geiger in my laboratory had examined it in detail. He found, in thin pieces of heavy metal, that the scattering was usually small, of the order of one degree. One day Geiger came to me and said, "Don't you think that young Marsden, whom I am training in radioactive methods, ought to begin a small research?" Now I had thought that, too, so I said, " Why not let him see if any alpha-particles can be scattered through a large angle?" I may tell you in confidence that I did not believe that they would be, since we knew the alpha-particle was a very fast, massive particle with a great deal of energy, and you could show that if the scattering was due to the accumulated effect of a number of small scatterings, the chance of an alpha-particle's being scattered backward was very small. Then I remember two or three days later Geiger coming to me in great excitement and saying "We have been able to get some of the alpha-particles coming backward " It was quite the most incredible event that ever happened to me in my life. It was almost as incredible as if you fired a 15-inch shell at a piece of tissue paper and it came back and hit you."

21 Rutherford s Results Over 98% of the α particles went straight through About 2% of the α particles went through but were deflected by large angles About 0.005% of the α particles bounced off the gold foil...as if you fired a 15 cannon shell at a piece of tissue paper and it came back and hit you.

22 Rutherford s Interpretation the Nuclear Model The atom contains a tiny dense center called the nucleus. The amount of space taken by the nucleus is only about 1/10 9 the volume of the atom. The nucleus has essentially the entire mass of the atom. The electrons weigh so little they give practically no mass to the atom. The nucleus is positively charged. The amount of positive charge balances the negative charge of the electrons. The electrons are dispersed in the empty space of the atom surrounding the nucleus.

23 Structure of the Nucleus Rutherford proposed that the nucleus had a particle that had the same amount of charge as an electron but opposite sign the proton. Because protons and electrons have the same amount of charge, for the atom to be neutral there must be equal numbers of protons and electrons.

24 Some Problems Electrons - negatively charged particles found in all atoms. Cathode rays are made of streams of electrons. The electron has a charge of 1.60 x C. The electron has a mass of 9.1 x g. Protons - subatomic particles found in the nucleus The proton has a charge of x C. The proton has a mass of x g. How could beryllium have four protons stuck together in the nucleus? If a beryllium atom has four protons, then it should weigh 4 amu; but it actually weighs 9.01 amu! Where is the extra mass coming from?

25 There Must Be Something Else! To answer these questions, Rutherford and Chadwick proposed that there was another particle in the nucleus it is called a neutron. Neutrons are subatomic particles with a mass = x g and no charge, and are found in the nucleus

26 A History of Atomic Models 400 B.C.E. (Democritus, a early atomist) 1804 (Dalton) 1903 (Thomson) 1932 (Chadwick) 1913 (Bohr) 1911 (Rutherford)

27 1 amu = 1 atomic mass unit

28 Quantum Model

29 The Number of Protons Defines the Element

30 Structure of the Nucleus Soddy (1913) discovered that the same element could have atoms with different masses, which he called isotopes. The observed atomic mass is a weighted average of the weights of all the naturally occurring atoms. The percentage of an element that is one isotope is called the isotope s natural abundance.

31 Atomic Mass (Weight) Carbon % C % C-13 Weighted average = amu trace % C-14 } Chlorine 75.5 % Cl % Cl 37} Weighted average = amu

32 Isotopes All isotopes of an element are chemically identical and undergo the exact same chemical reactions. All isotopes of an element have the same number of protons. Isotopes of an element have different masses. Isotopes of an element have different numbers of neutrons. Isotopes are identified by their mass numbers, which is the sum of all the protons and neutrons in the nucleus.

33 Isotopes Atomic number Number of protons = Z Mass Number A X Z Protons + neutrons = whole number = A Relative Abundance = relative amount found in a sample # neutrons = A-Z

34 Complete the table: C Mo Al Cs

35 Charged Atoms Ions are atoms which have acquired a charge through loss or gain of electrons. When atoms gain electrons, they become negatively charged ions, called anions. When atoms lose electrons, they become positively charged ions, called cations.

36 Complete the table S 2- Mg Al Br-

37 Periodic Trend in Ion Formation Nonmetals form anions. Anions named by changing the ending of the name to -ide. F + 1e fluorine atom F fluoride ion O + 2e oxygen atom O 2 oxide ion

38 Periodic Trend in Ion Formation Metals form cations. Cations are named the same as the metal. Na sodium atom Ca calcium atom Na + + 1e sodium ion Ca e calcium ion

39 Nonmetals Metals

Chapter 2 Atoms and Elements

Chapter 2 Atoms and Elements Chapter 2 Atoms and Elements Law of Conservation of Mass in a chemical reaction, matter is neither created nor destroyed total mass of the materials you have before the reaction must equal the total mass

More information

4.1 Structure of the Atom

4.1 Structure of the Atom 4.1 Structure of the Atom How do atoms differ from each other? What are atoms composed of? What are the subatomic particles? 2-1 Structure of the Atom Atoms actually are divisible. They are composed of

More information

The Atom. The Basic Building Block Atom from the Greek a-tom or indivisible (Democritus circa 500 BC) Four elements (earth, air, water, fire)

The Atom. The Basic Building Block Atom from the Greek a-tom or indivisible (Democritus circa 500 BC) Four elements (earth, air, water, fire) Atom Oxtoby hapter p - Basic Building Block Atom from the Greek a-tom or indivisible (Democritus circa 5 B) Four elements (earth, air, water, fire) Dalton (88) proposed modern atomic theory: All matter

More information

Early Atomic Models. Atoms: the smallest particle of an element that retains the properties of that element.

Early Atomic Models. Atoms: the smallest particle of an element that retains the properties of that element. Chapter 5 Early Atomic Models Atoms: the smallest particle of an element that retains the properties of that element. (Greek: atomos = indivisible) Democritus (Greek teacher in the 4 th century BC) First

More information

Democritus of Abdera. John Dalton. Dalton s Atom. Dalton s Atomic Theory Ancient Greece - 4th century BC. Eaglesfield, England

Democritus of Abdera. John Dalton. Dalton s Atom. Dalton s Atomic Theory Ancient Greece - 4th century BC. Eaglesfield, England Democritus of Abdera Ancient Greece - 4th century BC first suggested the existence of tiny fundamental particles that make up matter. atoms = indestructible did not agree with the current sci theory -

More information

Early Atomic Theory. Alchemy. The atom

Early Atomic Theory. Alchemy. The atom Early Atomic Theory Chapter 3 Democritus 460 BC- ~ 370 BC Nothing exists except atoms and empty space; everything else is opinion. Matter is composed of small indivisible particles, atomos meaning Indivisible

More information

Dalton Thompson Rutherford Bohr Modern Model ("Wave. Models of the Atom

Dalton Thompson Rutherford Bohr Modern Model (Wave. Models of the Atom Dalton Thompson Rutherford Bohr Modern Model ("Wave Models of the Atom Mechanical" Model) Aim: To discuss the scientists and their contributions to the current atomic model. Focus: Rutherford's Gold Foil

More information

EARLY VIEWS: The Ancient Greeks

EARLY VIEWS: The Ancient Greeks Feb 7 11:59 AM EARLY VIEWS: The Ancient Greeks Empedocles (c. 450 B.C.) proposed Four Element theory he thought that matter was composed of four elements: AIR, EARTH, FIRE and WATER elements mixed together

More information

Rhonda Alexander IC Science Robert E. Lee

Rhonda Alexander IC Science Robert E. Lee Rhonda Alexander IC Science Robert E. Lee Atom The smallest particle of an element that retains all of the chemical properties of the element. The Theory & Evidence for John Dalton s Atomic Theory: Around

More information

Atomic Theory. Democritus to the Planetary Model

Atomic Theory. Democritus to the Planetary Model Atomic Theory Democritus to the Planetary Model Democritus Greek philosopher (460-370 BCE) Believed in the philosophy of materialism With Leucippus, they though that matter can not be divided infinitely.

More information

Accelerated Chemistry Study Guide Atomic Structure, Chapter 3

Accelerated Chemistry Study Guide Atomic Structure, Chapter 3 Accelerated Chemistry Study Guide Atomic Structure, Chapter 3 Terms and definitions atom ion law of constant composition isotope atomic theory of matter mass number cathode ray tube atomic mass electron

More information

Chapter 4. The structure of the atom. AL-COS Objectives 1, 2,3,4,7, 10, 15, 20, 21, 22, 27and 28

Chapter 4. The structure of the atom. AL-COS Objectives 1, 2,3,4,7, 10, 15, 20, 21, 22, 27and 28 Chapter 4 The structure of the atom AL-COS Objectives 1, 2,3,4,7, 10, 15, 20, 21, 22, 27and 28 You ll learn to Identify the experiments that led to the development of the nuclear model of atomic structure

More information

Atomic Theory Timeline

Atomic Theory Timeline Atomic Theory Timeline Democritus 450 B.C. Democritus was a Greek philosopher who came to the conclusion that everything was made up of tiny particles. He used the term atomos. Unfortunately, since Democritus

More information

1. Based on Dalton s evidence, circle the drawing that demonstrates Dalton s model.

1. Based on Dalton s evidence, circle the drawing that demonstrates Dalton s model. Various models of the ATOM Dalton Model John Dalton developed the first atomic model in 1808. Before him people, mostly philosophers, had speculated about the smallest unit of matter and two theories prevailed.

More information

Nuclear Chemistry. Atomic Structure Notes Start on Slide 20 from the second class lecture

Nuclear Chemistry. Atomic Structure Notes Start on Slide 20 from the second class lecture Nuclear Chemistry Atomic Structure Notes Start on Slide 20 from the second class lecture The Birth of an Idea Democritus, 400 B.C. coined the term atom If you divide matter into smaller and smaller pieces,

More information

Chapter 2 Atoms and Elements

Chapter 2 Atoms and Elements 1 Chapter 2 Atoms and Elements Sec 2.3 Modern Atomic Theory and the Laws That Led to it Law of conservation of mass states that in a chemical reaction, matter is neither created nor destroyed. Law of definite

More information

CHAPTER 4 Atomic Structure

CHAPTER 4 Atomic Structure CHAPTER 4 Atomic Structure 4.1 Early Theories of Matter Earth, Water, Air, Fire Matter was thought to be infinitely divisible No method was available to test theories Democritus (460 B.C. 370 B.C.) First

More information

CHEMISTRY 11 UNIT REVIEW: ATOMIC THEORY & PERIODIC TRENDS

CHEMISTRY 11 UNIT REVIEW: ATOMIC THEORY & PERIODIC TRENDS CHEMISTRY 11 UNIT REVIEW: ATOMIC THEORY & PERIODIC TRENDS Atoms Atoms have protons and neutrons located in the nucleus of the atom. Electrons orbit around the nucleus in well-defined paths. Protons have

More information

Chapter 3 https://youtu.be/thndxfdkzzs?list=pl8dpuualjx tphzzyuwy6fyeax9mqq8ogr

Chapter 3 https://youtu.be/thndxfdkzzs?list=pl8dpuualjx tphzzyuwy6fyeax9mqq8ogr Chapter 3 https://youtu.be/thndxfdkzzs?list=pl8dpuualjx tphzzyuwy6fyeax9mqq8ogr The smallest particle of an element that retains the chemical properties of that element. Regions: Nucleus: very small region

More information

The structure of Atom III

The structure of Atom III The structure of Atom III Atomic Structure If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generations of creatures, what statement

More information

Atomic Theory. Why do we believe that all matter is made of atoms?

Atomic Theory. Why do we believe that all matter is made of atoms? Atomic Theory Why do we believe that all matter is made of atoms? 1. Law of definite composition: Compounds (like H 2 O) contain the same elements in the same proportions by mass regardless of the size

More information

Notes:&&Unit&4:&Atomics& & & & & & & & & & & & & & & & &

Notes:&&Unit&4:&Atomics& & & & & & & & & & & & & & & & & Name: RegentsChemistry:Mr.Palermo Notes:Unit4:Atomics! www.mrpalermo.com Name: $ Key$Ideas$ Themodernmodeloftheatomhasevolvedoveralongperiodoftimethroughtheworkofmany scientists.(3.1a) Eachatomhasanucleus,withanoverallpositivecharge,surroundedbyoneormorenegatively

More information

a. According to Dalton, what is inside the atom? Nothing, the atom it the smallest

a. According to Dalton, what is inside the atom? Nothing, the atom it the smallest Unit 3: Review SCIENTIFIC THEORIES Dalton theorized that atoms were the smallest particle and could not be divided. Atoms can bond with one another in whole number ratios to form compounds but cannot be

More information

Chapter 4 Atoms and Elements

Chapter 4 Atoms and Elements Atoms and Elements Experiencing Atoms Atoms are incredibly small, yet they compose everything. Atoms are the pieces of elements. Properties of the atoms determine the properties of the elements. 2 The

More information

Chapter 4 Atomic Structure. Chemistry- Lookabaugh Moore High School

Chapter 4 Atomic Structure. Chemistry- Lookabaugh Moore High School Chapter 4 Atomic Structure Chemistry- Lookabaugh Moore High School Section 4.1 Defining the Atom Democritus (460 B.C 370 B.C.) first used the term atomon to describe the smallest particle of matter possible.

More information

UNIT 4 ATOMIC THEORY

UNIT 4 ATOMIC THEORY UNIT 4 ATOMIC THEORY 1. Atomic theory: Dalton s model Thomson s model Rutherford s model Bohr s model Electron cloud model 2. Particles inside the atom Atomic number Mass number 3. Ions Cations Anions

More information

Democritus thought atoms were indivisible & indestructible Lacked experimental support 4 th century B.C.

Democritus thought atoms were indivisible & indestructible Lacked experimental support 4 th century B.C. Chapter 5 Democritus thought atoms were indivisible & indestructible Lacked experimental support 4 th century B.C. Democritus thought atoms were indivisible & indestructible Lacked experimental support

More information

CHEMISTRY 11 UNIT REVIEW: ATOMIC THEORY & PERIODIC TRENDS

CHEMISTRY 11 UNIT REVIEW: ATOMIC THEORY & PERIODIC TRENDS CHEMISTRY 11 UNIT REVIEW: ATOMIC THEORY & PERIODIC TRENDS Atoms Atoms have protons and neutrons located in the nucleus of the atom. Electrons orbit around the nucleus in well-defined paths. Protons have

More information

CHEMISTRY. Matter and Change. Table Of Contents. Section 4.1 Early Ideas About Matter. Unstable Nuclei and Radioactive Decay

CHEMISTRY. Matter and Change. Table Of Contents. Section 4.1 Early Ideas About Matter. Unstable Nuclei and Radioactive Decay CHEMISTRY 4 Table Of Contents Matter and Change Section 4.1 Early Ideas About Matter Chapter 4: The Structure of the Atom Section 4.2 Section 4.3 Section 4.4 Defining the Atom How Atoms Differ Unstable

More information

ATOMS AND ELEMENTS. Democritus 400 B.C. Atomic Theory of Matter. Dalton s Postulates (1803) Page 1

ATOMS AND ELEMENTS. Democritus 400 B.C. Atomic Theory of Matter. Dalton s Postulates (1803) Page 1 ATOMS AND ELEMENTS Democritus 400 BC Believed that matter was composed of invisible particles of matter he called atoms According to Democritus, atoms could not be broken into smaller particles Atomic

More information

Chapter 2. Conservation of Mass. Law of Definite Proportions. Group Activity. Draw you idea of what an atom looks like.

Chapter 2. Conservation of Mass. Law of Definite Proportions. Group Activity. Draw you idea of what an atom looks like. Group Activity Draw you idea of what an atom looks like. Chapter 2 Answer the following questions: How do you know what an atom looks like at the atomic level? How do scientists know what at atom looks

More information

CHAPTER 3. Atoms: The Building Blocks of Matter

CHAPTER 3. Atoms: The Building Blocks of Matter CHAPTER 3 Atoms: The Building Blocks of Matter Origins of the Atom Democritus: Greek philosopher (460 BC - 370 BC) Coined the term atom from the Greek word atomos Democritus believes that atoms were indivisible

More information

What is a theory? An organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena

What is a theory? An organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena Atomic Structure What is a theory? An organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena Early Theories Democritus: 4 B.C.: atom He

More information

Chapter 5. Early Atomic Theory and Structure

Chapter 5. Early Atomic Theory and Structure Chapter 5 Early Atomic Theory and Structure 1 5.1 Early thoughts ~ 400 B.C. Greek philosophers Empedocles all matter was composed of four elements earth, air, water, fire Democritus all forms of matter

More information

4/14/2013 ATOMIC STRUCTURE THE ATOMIC MODEL

4/14/2013 ATOMIC STRUCTURE THE ATOMIC MODEL ATOMIC STRUCTURE R E G E N T S C H E M I S T R Y M R S. T I L A R O HISTORY OF THE ATOM O L D A N D M O D E R N A T O M THE ATOMIC MODEL Model of the atom is based on indirect experimental data. Model

More information

Glencoe: Chapter 4. The Structure of the Atom

Glencoe: Chapter 4. The Structure of the Atom Glencoe: Chapter 4 The Structure of the Atom Section One: Early Ideas about Matter Atomists and Democritus : 400 B.C. From Thrace in Greece. Atoms- Uncut-Table Indivisible parts which cannot be broken

More information

An Introduction to Atomic Theory. VCE Chemistry Unit 1: The Big Ideas of Chemistry Area of Study 1 The Periodic Table

An Introduction to Atomic Theory. VCE Chemistry Unit 1: The Big Ideas of Chemistry Area of Study 1 The Periodic Table An Introduction to Atomic Theory VCE Chemistry Unit 1: The Big Ideas of Chemistry Area of Study 1 The Periodic Table From Democritus to Dalton Two thousand years ago, Democritus proposed that matter consisted

More information

Topic III Quest Study Guide

Topic III Quest Study Guide Topic III Quest Study Guide A. Early Concepts: Democritus: Democritus: Greek Philosopher 400 B.C. Matter is composed of atoms, which move through empty space Atoms are solid, homogeneous indestructible

More information

Bravo 15,000 kilotons

Bravo 15,000 kilotons UNIT 3 THE ATOM AND ATOMIC STRUCTURE Bravo 15,000 kilotons OBJECTIVES To determine the structure of any element on the periodic table Understand Dalton s Atomic Theory & Modern Atomic Theory Define and

More information

Early Atomic Theories and the Origins of Quantum Theory. Chapter 3.1

Early Atomic Theories and the Origins of Quantum Theory. Chapter 3.1 Early Atomic Theories and the Origins of Quantum Theory Chapter 3.1 What is Matter Made of? People have wondered about the answer to this question for thousands of years Philosophers Matter is composed

More information

Ch. 4 Notes THE STRUCTURE OF THE ATOM NOTE: Vocabulary terms are in boldface and underlined. Supporting details are in italics.

Ch. 4 Notes THE STRUCTURE OF THE ATOM NOTE: Vocabulary terms are in boldface and underlined. Supporting details are in italics. Ch. 4 Notes THE STRUCTURE OF THE ATOM NOTE: Vocabulary terms are in boldface and underlined. Supporting details are in italics. I. Early Ideas About Matter A. atom the smallest particle of an element retaining

More information

Chapter 1. Chemical Foundations

Chapter 1. Chemical Foundations Chapter 1 Chemical Foundations Chapter 1 Table of Contents (1.1) (1.2) (1.3) (1.4) (1.5) (1.6) (1.7) Chemistry: An atoms-first approach The scientific method The early history of chemistry Fundamental

More information

1 Development of the Atomic Theory

1 Development of the Atomic Theory CHAPTER 4 1 Development of the Atomic Theory SECTION Introduction to Atoms BEFORE YOU READ After you read this section, you should be able to answer these questions: What is the atomic theory? How has

More information

Development of Atomic Theory Elements of chemistry- Atoms, the building blocks of matter Video

Development of Atomic Theory Elements of chemistry- Atoms, the building blocks of matter Video Development of Atomic Theory Elements of chemistry- Atoms, the building blocks of matter Video 2 CH 4- Atoms 1 Discovering the Atom In this lesson we will take a look at the scientists who explored the

More information

PROGRESSION OF THE ATOMIC MODEL

PROGRESSION OF THE ATOMIC MODEL PROGRESSION OF THE ATOMIC MODEL By 1808, it was widely accepted that matter was made up of ELEMENTS, which consisted of tiny PARTICLES called ATOMS. After 2000 years - DEMOCRITUS was right all along John

More information

Chapter 2 Atoms, Ions, and the Periodic Table. Law of Conservation of Mass. Law of Conservation of Mass

Chapter 2 Atoms, Ions, and the Periodic Table. Law of Conservation of Mass. Law of Conservation of Mass Chapter 2 Atoms, Ions, and the Periodic Table Dalton s Atomic Theory Structure of the Atom Ions Atomic Mass The Periodic Table Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction

More information

Chapter 4: Atomic Structure Section 4.1 Defining the Atom

Chapter 4: Atomic Structure Section 4.1 Defining the Atom Chapter 4: Atomic Structure Section 4.1 Defining the Atom Early Models of the Atom atom the smallest particle of an element that retains its identity in a chemical reaction Democritus s Atomic Philosophy

More information

Physics 30 Modern Physics Unit: Atomic Basics

Physics 30 Modern Physics Unit: Atomic Basics Physics 30 Modern Physics Unit: Atomic Basics Models of the Atom The Greeks believed that if you kept dividing matter into smaller and smaller pieces, you would eventually come to a bit of matter that

More information

Unit 3. The Atom & Modern Atomic Theory

Unit 3. The Atom & Modern Atomic Theory Unit 3 The Atom & Modern Atomic Theory Theories of the Atom Early Models & Thoughts: Democritus Matter is made up of tiny particles called atoms. Smallest unit that retains the identity of the element

More information

Atomic Structure. Chapters 4, 8, Bravo 15,000 kilotons

Atomic Structure. Chapters 4, 8, Bravo 15,000 kilotons Atomic Structure Chapters 4, 8, 18.1-18.3 Bravo 15,000 kilotons What is an atom? Smallest unit of an element that retains all the properties of the element Can combine with other atoms to form compound

More information

The Nucleus Came Next

The Nucleus Came Next The Nucleus Came Next Ernest Rutherford The New Zealand born British chemist and physicist who became known as the father of nuclear physics. He discovered the atomic nucleus, and thereby pioneered the

More information

SNC1D1 History of the Atom

SNC1D1 History of the Atom SNC1D1 History of the Atom What is the atom? Atoms are the building block for all matter: Atoms make up elements! Elements combine to make compounds!2 ATOMIC MODEL TIMELINE 400 B.C PRESENT DAY ATOMIC MODEL

More information

Atomic Structure ATOMIC STRUCTURE. All matter is composed of atoms.

Atomic Structure ATOMIC STRUCTURE. All matter is composed of atoms. All matter is composed of atoms. ATOMIC STRUCTURE Understanding the structure of atoms is critical to understanding the properties of matter HISTORY OF THE ATOM DALTONS ATOMIC THEORY 1808 John Dalton suggested

More information

Atomic Structure. For thousands of years, people had many ideas about matter Ancient Greeks believed that everything was made up of the four elements

Atomic Structure. For thousands of years, people had many ideas about matter Ancient Greeks believed that everything was made up of the four elements An atom is the smallest particle of an element that retains its identity in a chemical reaction. Although early philosophers and scientists could not observe individual atoms, they were still able to propose

More information

Unit 3: Atomic Structure. Particle Charge Location in the Atom Mass

Unit 3: Atomic Structure. Particle Charge Location in the Atom Mass Unit 3: Atomic Structure Name: Basics of the Atom Particle Charge Location in the Atom Mass a.m.u.: unit used to measure mass of atoms atomic number: mass number: To find net charge on an atom, consider

More information

Atomic Theory The earliest recorded information about changes in matter come from the early Greeks so it is often referred to as the Greek Model. Anci

Atomic Theory The earliest recorded information about changes in matter come from the early Greeks so it is often referred to as the Greek Model. Anci Atomic Theory A theory - a thoroughly tested explanation. With more information the explanations change, hopefully the explanations get better, explain more behaviors. While the old theory still works,

More information

Atomic Structure. ppst.com

Atomic Structure. ppst.com Atomic Structure ppst.com Defining the Atom The Greek philosopher (460 B.C. 370 B.C.) was among the first to suggest the existence of atoms (from the Greek word ) He believed that atoms were and His ideas

More information

Atomic Structure. How do you discover and study something you can t see?

Atomic Structure. How do you discover and study something you can t see? Atomic Structure How do you discover and study something you can t see? WHAT IS A THEORY? A hypothesis is a proposed explanation made as a starting point for further investigation (It s bright outside

More information

Early Models of the Atom

Early Models of the Atom Early Models of the Atom An atom is the smallest particle of an element that retains its identity in a chemical reaction. Although early philosophers and scientists could not observe individual atoms,

More information

The term valent means outermost, therefore only the electrons on the outermost shell are called valent.

The term valent means outermost, therefore only the electrons on the outermost shell are called valent. The atom is the smallest basic unit of an element which possesses the properties of the element. Structure of the Atom The term valent means outermost, therefore only the electrons on the outermost shell

More information

Origins of the Atom. Atoms: The Building Blocks of Matter. Let s Get Ready to Rumble. Aristotle s Theory of the Atom CHAPTER 3

Origins of the Atom. Atoms: The Building Blocks of Matter. Let s Get Ready to Rumble. Aristotle s Theory of the Atom CHAPTER 3 Origins of the Atom CHAPTER 3 Atoms: The Building Blocks of Matter Let s Get Ready to Rumble The idea of the atom was met with great skepticism, especially among great thinkers. The most vocal critic of

More information

The Story of the Atom. A history of atomic theory over many years

The Story of the Atom. A history of atomic theory over many years The Story of the Atom A history of atomic theory over many years Democritus Many years ago, between 460BC and 370BC the Greek philosophers wondered what we were made of. Leucippus and Democritus came up

More information

IB Chemistry : Atomic Structure & History with Boardworks Enabled Interactives

IB Chemistry : Atomic Structure & History with Boardworks Enabled Interactives Atomic Structure Contents INTRODUCING ATOMS SUB ATOMIC PARTICLES HISTORY ATOMIC # & MASS # AVERAGE ATOMIC MASS MASS SPECTROMETER ELECTRON CONFIGURATION ISOTOPES SUMMARY ACTIVITIES ELEMENTS DIFFERENT TYPES

More information

Understanding the Atom

Understanding the Atom Name Date Period 3.1 Discovering Parts of an Atom Directions: On the line before each statement, write correct if the statement is correct or not correct if the statement is not correct. If the statement

More information

ATOM. Rich -Paradis. Early Thoughts Aristotle-- Continuous theory. Matter can be divided indefinitely. Greeks

ATOM. Rich -Paradis. Early Thoughts Aristotle-- Continuous theory. Matter can be divided indefinitely. Greeks ATOM Early Thoughts Aristotle-- Continuous theory Greeks Matter can be divided indefinitely matter is made up of particles--4 elements 4 elements --air--fire--water- -- earth Democritus --Discontinuous

More information

Chapter 3: Atomic Theory

Chapter 3: Atomic Theory Chapter 3: Atomic Theory and Elements, Atoms, Compounds & Ions A. The Elements All of the materials in the universe can be chemically broken down into about 100 different elements. 1. Element can have

More information

The Structure of the Atom

The Structure of the Atom Main Ideas Atoms contain positive and negative particles. Atoms have small, dense, positively-charged nuclei. A nucleus contains protons and neutrons. The radii of atoms are expressed in picometers. FIGURE

More information

CHAPTER 3. Chemical Foundations

CHAPTER 3. Chemical Foundations CHAPTER 3 Chemical Foundations 3.1 THE ELEMENTS 118 elements in 92 occur naturally, the rest are synthesized All matter in the universe can be chemically broken down into elements Compounds are made by

More information

Democritus 460 BC 370 BC. First scholar to suggest that atoms existed. Believed that atoms were indivisible and indestructible.

Democritus 460 BC 370 BC. First scholar to suggest that atoms existed. Believed that atoms were indivisible and indestructible. Democritus 460 BC 370 BC First scholar to suggest that atoms existed. Believed that atoms were indivisible and indestructible. Democritus 460 BC 370 BC Problems with theory: 1. Did not explain chemical

More information

SCH3U1 This presentation and more can be found at

SCH3U1 This presentation and more can be found at SCH3U1 Today s Learning goals: Review history of the atomic model Practice using standard atomic notation Introduce radioisotopes This presentation and more can be found at http://lorenowicz.weebly.com

More information

History of Atomic Theory

History of Atomic Theory Unit 2 The Atom History of Atomic Theory A. Democritus and Aristotle Democritus named the "atom" - means indivisible Dalton (with work of Lavoisier, Proust, and Gay-Lussac) 1. atomic theory - first based

More information

Name: Date: Blk: Dalton Thomson Rutherford Bohr THOMSON

Name: Date: Blk: Dalton Thomson Rutherford Bohr THOMSON Name: Date: Blk: NOTES: ATOMIC STRUCTURE I. History of the Atom Dalton Thomson Rutherford Bohr 1803 1897 1909 1913 1. DALTON - everything is made of atoms - different elements combine to form compounds

More information

Chemistry Chapter 3. Atoms: The Building Blocks of Matter

Chemistry Chapter 3. Atoms: The Building Blocks of Matter Chemistry Chapter 3 Atoms: The Building Blocks of Matter I. From Philosophical Idea to Scientific Theory History of the Atom The Ancient Greeks were the first to come up with the idea of the atom. Democritus

More information

Unit 1, Lesson 01: Summary of Atomic Structure so far

Unit 1, Lesson 01: Summary of Atomic Structure so far Unit 1, Lesson 01: Summary of Atomic Structure so far Atoms are made of sub-atomic particles: Protons: found in the nucleus, charge of 1+, mass of 1 amu (u) Neutrons: found in nucleus, no charge, mass

More information

DescribeDemocritus s Democritus s ideas

DescribeDemocritus s Democritus s ideas Atomic Structure Section 4.1 Defining the Atom DescribeDemocritus s Democritus s ideas about atoms. Section 4.1 Defining the Atom Explain Dalton s atomic theory. Section 4.1 Defining the Atom Identifywhat

More information

The modern model of the atom has evolved over a long period of time through the work of many scientists.(3.1a) Each atom has a nucleus, with an

The modern model of the atom has evolved over a long period of time through the work of many scientists.(3.1a) Each atom has a nucleus, with an REGENTS CHEMISTRY 1 The modern model of the atom has evolved over a long period of time through the work of many scientists.(3.1a) Each atom has a nucleus, with an overall positive charge, surrounded by

More information

ATOMIC STRUCTURE. Name: Period: Date: 1) = a generalization of scientific observations that what happens (does explain)

ATOMIC STRUCTURE. Name: Period: Date: 1) = a generalization of scientific observations that what happens (does explain) ATOMIC STRUCTURE Name: Period: Date: I. LAW vs. THEORY: 1) = a generalization of scientific observations that what happens (does explain) 2) (model) = a set of assumptions used to explain observations

More information

Section 3.1 Substances Are Made of Atoms

Section 3.1 Substances Are Made of Atoms Section 3.1 Substances Are Made of Atoms Objectives: 1. State the three laws that support the existence of atoms. 2. List the five principles of John Dalton s atomic theory. Vocabulary: law of definite

More information

Honors Chemistry Unit 2: The Atom & Its Nucleus

Honors Chemistry Unit 2: The Atom & Its Nucleus Honors Chemistry Unit 2: The Atom & Its Nucleus (2017-2018) Bunsen, I must tell you how excellent your study of chemical spectroscopy is, as is your pioneer work in photochemistry but what really impresses

More information

Chapter 4. Atomic Structure

Chapter 4. Atomic Structure Chapter 4 Atomic Structure Warm Up We have not discussed this material, what do you know already?? What is an atom? What are electron, neutrons, and protons? Draw a picture of an atom from what you know

More information

Name Chemistry-PAP Per. Notes: Atomic Structure

Name Chemistry-PAP Per. Notes: Atomic Structure Name Chemistry-PAP Per. I. Historical Development of the Atomic Model Ancient Greek Model Notes: Atomic Structure Democritus (460-370 BC) was an ancient Greek philosopher credited with the first particle

More information

3.1 Early History of Atomic Theories

3.1 Early History of Atomic Theories Figure 1 In Dalton s atomic model, an atom is a solid sphere, similar to a billiard ball. This simple model is still used today to represent the arrangement of atoms in molecules. DID YOU KNOW? William

More information

The History of the Atom. How did we learn about the atom?

The History of the Atom. How did we learn about the atom? The History of the Atom How did we learn about the atom? The Atomic Theory of Matter All matter is made up of fundamental particles. What does fundamental mean? The Greek Philosophers, 400 B.C. Democritus

More information

2.1 Atomic Theory of Matter

2.1 Atomic Theory of Matter Chapter 2 2.1 Atomic Theory of Matter The theory that atoms are the fundamental building blocks of matter re-emerged in the early nineteenth century, championed by John Dalton. Law of Conservation of Mass

More information

Name... Class... Date... In this activity you will have an opportunity to explore the nuclear model of the atom by building your own.

Name... Class... Date... In this activity you will have an opportunity to explore the nuclear model of the atom by building your own. Model of an atom Specification references: C1.1.4 Relative electrical charges of subatomic particles C1.1.5 Size and mass of atoms WS 1.2 Aims In this activity you will have an opportunity to explore the

More information

Atomic Class Packet Unit 3

Atomic Class Packet Unit 3 The modern model of the atom has evolved over a long period of time through the work of many scientists.(3.1a) Each atom has a nucleus, with an overall positive charge, surrounded by one or more negatively

More information

5 Early Atomic Theory and Structure

5 Early Atomic Theory and Structure 5 Early Atomic Theory and Structure Chapter Outline 5.1 5.2 Electric Charge A. Discovery of Ions 5.3 Subatomic Parts of the Atom Lightning occurs when electrons move to neutralize charge difference between

More information

Chapter 5. Early Atomic Theory and Structure

Chapter 5. Early Atomic Theory and Structure Chapter 5 Early Atomic Theory and Structure Introduction to General, Organic, and Biochemistry 10e John Wiley & Sons, Inc Morris Hein, Scott Pattison, and Susan Arena Lightning occurs when electrons move

More information

What is the current atomic model?

What is the current atomic model? 4.1 Atoms Basic Units of Matter What is the current atomic model? Matter is anything that has mass and takes up space, such as gases, solids, and liquids. Matter is not sound, heat, or light these are

More information

THE BIG IDEA: ELECTRONS AND THE STRUCTURE OF ATOMS

THE BIG IDEA: ELECTRONS AND THE STRUCTURE OF ATOMS HONORS CHEMISTRY - CHAPTER 4 ATOMIC STRUCTURE OBJECTIVES AND NOTES - V10 NAME: DATE: PAGE: THE BIG IDEA: ELECTRONS AND THE STRUCTURE OF ATOMS Essential Questions 1. What components make up an atom? 2.

More information

UNIT 4 NOTES: ATOMIC THEORY & STRUCTURE

UNIT 4 NOTES: ATOMIC THEORY & STRUCTURE S T U D E N T N O T E S P r e - A P C h e m i s t r y U N I T 4 Page 1 NAME PERIOD UNIT 4 NOTES: ATOMIC THEORY & STRUCTURE STUDENT OBJECTIVES: Your fascinating teachers would like you amazing learners

More information

What is matter? Matter is anything that has mass and takes up space. What is matter made of??

What is matter? Matter is anything that has mass and takes up space. What is matter made of?? What is matter? Matter is anything that has mass and takes up space What is matter made of?? Atoms. All matter is made of atoms. Atoms are the building blocks of Matter Remember???? The Cell theory - 3

More information

All are made of atoms. The, your and even are made of atoms. Atoms are. One atom is only one of a meter wide!

All are made of atoms. The, your and even are made of atoms. Atoms are. One atom is only one of a meter wide! Name: Atoms & The Periodic Table WHAT IS AN ATOM? What is an atom? All are made of atoms. The, your and even are made of atoms. Atoms are. One atom is only one of a meter wide! DEMOCRITIS The idea of an

More information

Atomic Theory: Early Models of the Atom:

Atomic Theory: Early Models of the Atom: Atomic Theory: Our next job in Chemistry 11 is to learn about what matter is made of. After we have done this, we can start to understand why matter behaves the way it does. Everything that has volume

More information

Basic Concepts of Chemistry Notes for Students [Chapter 2, page 1] D J Weinkauff - Nerinx Hall High School

Basic Concepts of Chemistry Notes for Students [Chapter 2, page 1] D J Weinkauff - Nerinx Hall High School Basic Concepts of Chemistry Notes for Students [Chapter 2, page 1] Chapter 2 Chemical Foundations: Elements, Atoms and Ions Section 2-1: The Elements Ultimately all substances in the universe can be broken

More information

Atomic Structure. Chemistry Mr. McKenzie

Atomic Structure. Chemistry Mr. McKenzie Atomic Structure Chemistry Mr. McKenzie How was the understanding of the atom developed? John Dalton (1766-1844) - developed a model to explain observations made at the time 1. Elements are made of tiny

More information

The Atom. protons, neutrons, and electrons oh my!

The Atom. protons, neutrons, and electrons oh my! The Atom protons, neutrons, and electrons oh my! What s an Atom? An atom is the smallest physical particle of an element that still retains the properties of that element. How Big is an Atom? At sea level,

More information

Vocabulary QUIZ: 1. The total number of particles in the nucleus 2. 1 / 12

Vocabulary QUIZ: 1. The total number of particles in the nucleus 2. 1 / 12 Sep 29 11:29 AM Vocabulary QUIZ: 1. The total number of particles in the nucleus 2. 1 / 12 th of the mass of a carbon atom 3. The weighted average mass of all the isotopes of a particular element 4. A

More information

Exam Accelerated Chemistry Study Sheet Chap 04 The Atom/Periodic Table

Exam Accelerated Chemistry Study Sheet Chap 04 The Atom/Periodic Table Exam Accelerated Chemistry Study Sheet Chap 04 The Atom/Periodic Table Name /87 TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. Correct the False statements by changing

More information

Particle Theory of Matter. By the late 1700s, scientists had adopted the Particle Theory of Matter. This theory states that:

Particle Theory of Matter. By the late 1700s, scientists had adopted the Particle Theory of Matter. This theory states that: Particle Theory of Matter By the late 1700s, scientists had adopted the Particle Theory of Matter. This theory states that: all matter is made up of very tiny particles each pure substance has its own

More information