Name Chemistry-PAP Per. Notes: Atomic Structure
|
|
- Meryl Nelson
- 6 years ago
- Views:
Transcription
1 Name Chemistry-PAP Per. I. Historical Development of the Atomic Model Ancient Greek Model Notes: Atomic Structure Democritus ( BC) was an ancient Greek philosopher credited with the first particle theory of matter. Democritus theory included the following ideas: Matter is made of tiny, solid, indivisible particles which he called atoms (from atomos, the Greek word for indivisible). Different kinds of atoms have different sizes and shapes. Different properties of matter are due to the differences in size, shape, and movement of atoms. Democritus ideas, though correct, were widely rejected by his peers, most notably Aristotle ( BC). Aristotle was a very influential Greek philosopher who had a different view of matter. He believed that everything was composed of the four elements earth, air, fire, and water. Because at that time in history, Democritus ideas about the atom could not be tested experimentally, the opinions of well-known Aristotle won out. Democritus ideas were not revived until John Dalton developed his atomic theory in the 19 th century! By the 1700 s, scientists had begun to study chemical reactions in detail, and the results of these experiments provided the empirical basis for Dalton s Atomic Theory. He is known as the Father of Atomic Theory because he was the first person who was able to draw sweeping conclusions about the behavior of atoms from this experimental evidence. John Dalton s Atomic Theory (1808) 1) All matter is composed of extremely small particles called atoms. 2) Atoms of the same element are identical and have the same properties; atoms of different elements have different properties. 3) Atoms are indivisible and indestructible. Atoms cannot be created, destroyed, or changed into another element. 4) Atoms of different elements combine in whole number ratios to form compounds. This is known as the Law of Definite Proportions. 5) When atoms react, they can sometimes combine in more than one whole number ratio to form different compounds. This is known as the Law of Multiple Proportions. Since Dalton s time, we have learned more about the atom, providing more information about #2 and #3 above: Atoms are divisible into even smaller subatomic particles (protons, neutrons, electrons). Atoms of the same element are not all identical. They can have different masses because they differ in the number of neutrons. These varieties of one element are called isotopes of that element. During nuclear reactions (which are fundamentally different from chemical reactions), it is possible for one atom to be transformed into a different type of atom. JJ Thomson and the Plum Pudding Model JJ Thomson discovered the first subatomic particle (1897) using cathode ray tubes. Thomson noted that cathode rays were deflected away from a negatively charged object and concluded that the particles in cathode rays were negatively charged. These particles were later named electrons. His discoveries led to the formulation of the Plum Pudding Model of the atom. Electrons were thought to be stuck into a lump of positively charged material. 1
2 Ernest Rutherford and the Gold Foil Experiment In 1906, Rutherford did experiments bombarding thin gold foil with alpha particles (helium nuclei, positively charged) from a radioactive source (polonium). He observed that most of the particles passed through the foil, but every once in a while a particle was deflected, or even bounced off the foil! Rutherford inferred there must be a small amount of space densely-packed with a positive charge, since it repelled the positive alpha particles. He named this structure the nucleus. Therefore, Rutherford is credited with being the first person to recognize the nuclear atom. He also inferred based on his results that the volume of the nucleus is very small compared to the total volume of the atom. Niehls Bohr and the Planetary Model Developed the Bohr model of the atom (1913) in which electrons are restricted to specific energies and follow paths called orbits a fixed distance from the nucleus. This is similar to the way the planets orbit the sun. However, the quantum model later showed that electrons do not have neat orbits like the planets. Diagram of Bohr model: Quantum Mechanical Model This is the current model of the atom. It is a mathematical model. It was developed in the 1920s by the work of many scientists, including de Broglie, Schrödinger, Pauli, and Heisenberg. In the quantum model, electrons are described as standing waves of energy. Electrons exist in regions of space around the nucleus which are called orbitals. The paths of the electrons within the orbitals are random and therefore cannot be predicted. We can only talk about the probability of an electron being in a certain region. Electrons have a high probability of being located near the nucleus. 2
3 II. Facts about the Atom The atom is the smallest part of an element that retains the properties of that element. The atom is made of 2 parts: the nucleus and the electron cloud. The nucleus is composed of neutrons (neutral) and protons (positively charged). The electrons are found in the electron cloud and they are negatively charged. Atoms are overall neutral because they contain the same number of protons and electrons. Because most of mass of atom is located in a very small volume, nuclei have incredibly high densities. Particle Symbol Charge Mass (grams) Where found Electron e x g In electron cloud Proton p x g Nucleus Neutron n x g Nucleus If an electron weighed the same as a dime, a proton would weigh the same as a gallon of milk. The nucleus contains almost all of the atom s mass, but the electron cloud is responsible for almost all of the volume. If this positive particle were the proton in a hydrogen atom, it would take a screen 1 mile across to display the electron's orbit: III. Subatomic Particles and Isotopes The of an element is the number of in the nucleus. This number identifies the element. Ex.: an atom has 38 protons, it must be Elements are placed on the periodic table in order of atomic number. Isotopes Isotopes are atoms of the same element that have different numbers of. Hydrogen has three : 1. Protium (hydrogen-1): 1 proton, 0 neutrons (99.985% of all H) 2. Deuterium: (hydrogen-2): 1 proton, 1 neutron (0.015% of all H) 3. Tritium: (hydrogen-3): 1 proton, 2 neutrons (very small amount, radioactive) 3
4 Mass Number and Average Atomic Mass The is defined as the sum of the number of and in an isotope. Ex.: an isotope of chlorine contains 17 protons and 18 neutrons The mass # = Isotope notation: isotopes are identified by specifying their mass # in one of two ways. 1) the mass # is written with a hyphen after the of the element Ex.: 2) the chemical symbol of the element is written and the mass # is designated as a in the upper left-hand corner (atomic # at lower left-hand corner) Ex.: Practice Determine the # of p +, n 0, and e - for carbon-13 Write isotope notation for an element with 7 electrons and 9 neutrons in 2 ways. Most elements occur as of isotopes, which we take into account when calculating average. Average atomic mass is the average of the atomic masses of the naturally-occurring of an element. It is what is shown on the. To calculate a weighted average: 1) Multiply the mass of each isotope by its % abundance in decimal form 2) Take the sum of the above for all isotopes Practice 1. Lithium exists as 2 isotopes in nature: lithium-6 with a mass of amu (7.5%) and lithium-7 with a mass of amu (92.5%). Determine the average atomic mass of lithium. 2. Magnesium has three naturally-occurring isotopes as shown in the table below. Determine the average atomic mass of magnesium. Isotope Mass (amu) % abundance Magnesium Magnesium Magnesium Neon has 2 isotopes: neon-20 and neon-22. Use the information from the periodic table to determine which occurs in greater abundance. 4
5 IV. Isotopes and Natural Radioactive Decay Many isotopes are radioactive. This means they undergo radioactive decay. They naturally break down into a smaller element and release particles and energy (radiation) in the process. The reason they break down is that their nucleus is unstable, due to an unfavorable neutron:proton ratio. They decay to form a new element with a more stable neutron:proton ratio. 2 simple types of radioactive decay: Alpha decay: releases an alpha (α) particle (a helium nucleus): 4 2 He = alpha particle Example: 238 U 234 Th + 4 He notice that mass # and atomic # are conserved Beta decay: a neutron in the original atom decays to form a proton and an electron: 0 e = beta particle -1 1 n 1 p + 0 e The neutron is represented in the original element; the proton is represented in the new element. The overall result is that a beta (β) particle (a high-speed electron) is released: Example: 210 Pb 210 Bi + 0 e notice that mass # and atomic # are conserved In nuclear equations, the total of the atomic numbers and the total of the mass numbers must be equal on both sides of the equation. Notice that in both alpha and beta decay, when the atomic number changes, the identity of the element changes. This is called a transmutation. Both kinds of decay also release gamma (γ) radiation in the process. Gamma radiation is pure energy, not a particle, so it is not ordinarily represented in the equation. Comparison of alpha and beta particles and gamma radiation: Alpha Beta Gamma More massive Less massive No mass; all energy Cause the most damage over a short range Cause less damage over a short range Cause the least damage over a short range Least able to penetrate surfaces; stopped by a piece of paper More able to penetrate surfaces; stopped by a thin sheet of aluminum foil Most able to penetrate surfaces; stopped by a thick sheet of lead Half-life Half-life is the time within which any particular radioactive atom has a chance of undergoing decay. Another more common way to define half-life is the time it takes for half of a sample to undergo radioactive decay. Half-life can vary greatly, depending on the isotope. Examples: half-life of polonium-212 is 3 x 10 7 seconds; half-life of uranium-238 is 4.5 billion years. 5
6 Half Life Calculations A formula exists for use in half-life calculations; however, mastery of the formula requires a background knowledge of the rules of logarithms, on which the vast majority of students have not yet received instruction. Therefore, we will be teaching you to solve the problems with a chart method instead. The chart method will be sufficient to solve the types of problems we will give you in this class. 1. A radioactive isotope has a half-life of 330 years. If the initial amount of the isotope was 800 g, how much remains after 1320 years? 2. The same isotope (half-life 330 years) has been decaying for 1650 years (elapsed time), and g remains. What was the initial amount of the sample? 3. A sample of a radioactive isotope that was initially 1600 g decayed for 25,000 years. If 50 g remains after this time, what is the half-life of the isotope? 4. A radioactive isotope with a half-life of 3 minutes decayed from 100 g to 25 g. How much time elapsed? Nuclear Fission Occurs by bombardment of U-235 or Pu-239 with neutrons (fissionable isotopes). For example, U-235 splits into several different smaller elements and also releases more neutrons and a large quantity of energy. If enough of the fissionable isotope is present, the neutrons will sustain a chain reaction, which can result in a nuclear explosion if the situation is unchecked. Diagram of fission reaction on next page: 6
7 Graphic illustration of fission reaction: Nuclear fission releases huge quantities of energy; gram for gram, at least a million times more than the energy produced in any chemical reaction. Why are nuclear fission reactions so powerful? Nuclear reactions are fundamentally different from ordinary chemical reactions. Chemical reactions involve breaking chemical bonds in molecules and forming new ones. When bonds in the products are stronger than bonds in the reactants, energy is released. But during this process, the nucleus of each atom involved remains unchanged. Nuclear fission reactions involve breaking apart an original nucleus and forming several new nuclei. During this process, a small amount (less than 0.1%) of the mass of the original atom is converted to energy. Even small amounts of mass converted result in large amounts of energy released. Einstein explained this conversion with his famous equation E = mc 2. E = energy released (Joules) m = mass converted (kg) c = speed of light, 3.0 x 10 8 m/s To give you an idea, if 1 g of matter were completely converted to energy, the energy released would equal that produced from burning 700,000 gallons of gasoline! Nuclear reactors: controlled nuclear fission reactions used to generate power Nuclear weapons: uncontrolled nuclear fission reactions WWII: Little boy bomb: U-235 Hiroshima ; Fat man bomb: Pu-239 Nagasaki 7
8 Nuclear Fusion Nuclear fusion involves forcing 2 relatively small nuclei (hydrogen) to combine (or fuse) into one nucleus (helium). As with fission, the amount of energy released can be huge, due to mass-energy conversion. In fact, nuclear fusion liberates 3-10 times more energy than fission. Nuclear fusion powers the stars, including our sun. In this way, nuclear fusion can be thought of as the source of almost all the energy on the planet. Scientists have not yet found a way to sustain a beneficial nuclear fusion reaction on earth. The major difficulty is maintaining the extremely high temperatures necessary for fusion to occur, while at the same time containing the reactants and fused nuclei. Examine the four reactions to the right. Can you identify the fission reaction? Which one is the fusion reaction? Which one is the chemical (NOT nuclear) reaction? How is this one different from the other three? 8
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 informationMass number i. Example U (uranium 235) and U (uranium 238) atomic number e. Average atomic mass weighted of the isotopes of that element i.
CP NT Ch. 4&25 I. Atomic Theory and Structure of the Atom a. Democritus all matter consists of very small, indivisible particles, which he named i. Atom smallest particle of an element that retains all
More informationAtomic Structure & Nuclear Chemistry Unit 3 Notes
Atomic Structure & Nuclear Chemistry Unit 3 Notes Academic Chemistry Name 52 24 Cr Mass Number Symbol Atomic Number Unit #3 Test Date You can never learn less, you can only learn more. R. Buckminster Fuller
More informationUnit 2: Atomic Theory Notes
Unit 2: Atomic Theory Notes The changing of a substance into one or more new substances is known as a chemical reaction. Law of conservation of mass: mass is neither created nor destroyed during ordinary
More informationNuclear 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 information2. Electrons: e - charge = negative -1 mass ~ 0
Notes Ch. and 5: Atomic Structure and Nuclear Chemistry History and Structure the Nuclear Atom The Atom smallest particle an element that retains all properties the element I. Early Models the Atom A.
More informationUnit 1 Atomic Structure
Unit 1 Atomic Structure 3-1 The Atom: From Philosophical Idea to Scientific Theory I. Atomic Theory A. Modern Atomic Theory 1. All matter is made up of very tiny particles called atoms 2. Atoms of the
More informationUnit 1 Atomic Structure
Unit 1 Atomic Structure Defining the Atom I. Atomic Theory A. Modern Atomic Theory 1. All matter is made up of very tiny particles called atoms 2. Atoms of the same element are chemically alike 3. Individual
More informationChapter 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 informationThe 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 informationAtomic 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 informationDalton 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 informationCHAPTER 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 informationStructure of the Nuclear Atom
Structure of the Nuclear Atom I. The II. A. The is the smallest particle of an element that retains its of the element. History of the Atom A. Democritus 1. Democritus (460 B.C. 370 B.C) was the first
More informationCHEMISTRY 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 informationAtomic 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 informationCHEMISTRY. 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 informationAtomic 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 informationChapter 4 The Atom. Philosophers and scientists have proposed many ideas on the structure of atoms.
Chapter4 TheAtom 4.1 Early Models of the Atom An atom is the smallest particle of an element that retains its identity in a chemical reaction. Philosophers and scientists have proposed many ideas on the
More informationChapter 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 informationHonors 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 informationGet out your diagram from your research paper. Get out a sheet of paper to take some notes on.
Bellwork: Get out your diagram from your research paper. Get out a sheet of paper to take some notes on. Fill in the Following Table in your notes (assume an atom unless otherwise stated: Symbol Protons
More informationAtomic 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 informationUnit 2 Atomic Structure and Nuclear Chemistry
Chemistry 1 West Linn High School Unit 2 Packet and Goals Name: Period: Unit 2 Atomic Structure and Nuclear Chemistry Unit Goals: As you work through this unit, you should be able to: 1. describe Dalton
More informationDescribeDemocritus 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 informationChemistry 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 informationChapter 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 informationEarly 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 informationCh. 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 informationChapter 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 informationDevelopment 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 informationtomic tructure Chapter 3
tomic tructure Chapter 3 Early Theories of Matter 460 BC Democritus Proposed the matter was not infinitely divisible. Believed matter composed of particles called atoms. Early Theories of Matter Aristotle
More informationCHAPTER 3 THE ATOM. 1. Matter is composed extremely small particles called atoms
CHAPTER 3 THE ATOM Read pgs. 107-110 I. History Democritus Greek philosopher, 400 B.C., said all matter is made up of small, indivisible particles he called atoms (Greek for indivisible ). He wasn t believed
More informationTopic 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 informationThe Structure of the Atom
The Structure of the Atom Section 4.1 Early Theories of Matter In your textbook, read about the philosophers, John Dalton, and defining the atom. For each statement below, write true or false. 1. Ancient
More informationAtomic Theory Development
Atomic Theory Development Born as early as 400 BC, it took more than 2000 years before Science was ready to accept the idea of atomic structure of matter and another 150 years to develop a good model!
More informationHistory 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 informationThe 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 informationDemocritus & Leucippus (~400 BC) Greek philosophers: first to propose that matter is made up of particles called atomos, the Greek word for atoms
AP Chemistry Ms. Ye Name Date Block The Evolution of the Atomic Model Since atoms are too small to see even with a very powerful microscope, scientists rely upon indirect evidence and models to help them
More informationScientist wanted to understand how the atom looked. It was known that matter was neutral. It was known that matter had mass
Atom Models Scientist wanted to understand how the atom looked It was known that matter was neutral It was known that matter had mass They used these ideas to come up with their models, however science
More information4.1 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 informationAtomic 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 informationAtoms and their structure
Atoms and their structure History of atomic theory Not the history of atom, but the idea of the atom Original idea Ancient Greece (400 B.C..) Democritus and Leucippus Greek philosophers Another Greek Aristotle
More informationUnderstanding 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 informationSNC1D1 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 informationChapter 11 Study Questions Name: Class:
Chapter 11 Study Questions Name: Class: Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. The discovery of which particle proved that the atom
More informationChapter #1 - Atomic Structure
Chapter #1 - Atomic Structure Atomic Theories Democritus (460-340 BC) Democritus believed that all matter consisted of extremely small particles that could not be divided. He called them atoms from the
More informationEarly 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 informationAtomic Structure. A model uses familiar ideas to explain unfamiliar facts observed in nature.
Atomic Structure 1 2 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. A model uses familiar
More informationParticle 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 informationAn atom is the smallest physical particle of an element that still retains the properties of that element.
Unit 3.1 An atom is the smallest physical particle of an element that still retains the properties of that element. At sea level, one cubic centimeter of air (size of a sugar cube, or marble) will have
More informationCHEMISTRY 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 informationJJ Thompson (1897) Robert Millikan (1909)
Atomic Structure Matter Consists of Particles Aristotle Democritus John Dalton 183 I am a genius! Atomic Theory of Matter based on the following postulates: 1) Each element is composed of particles called
More informationAtomic 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 informationEARLY 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 informationThe 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 informationWhat 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 informationBravo 15,000 kilotons
Bravo 15,000 kilotons All matter is composed of atoms Atoms cannot be subdivided, created, or destroyed in ordinary chemical reactions. However, these changes CAN occur in nuclear reactions! Atoms of an
More informationAtomic Theory. Contribution to Modern Atomic Theory
Alief High School Chemistry STAAR Review Reporting Category 2: Atomic Structure and Nuclear Chemistry C.6.A Understand the experimental design and conclusions used in the development of modern atomic theory,
More informationUNIT 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 informationBravo 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 information5 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 informationChapter 3 Atoms: The Building Blocks of Matter. Honors Chemistry 412
Chapter 3 Atoms: The Building Blocks of Matter Honors Chemistry 412 Foundations of Atomic Theory Democritus Greek Philosopher 460-370 B.C. Stated Matter could be divided into smaller & smaller particles
More informationVocabulary 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 informationChapter 4. Atomic Structure
Chapter 4 Atomic Structure Warm Up We have not yet discussed this material, but what do you know already?? What is an atom? What are electron, neutrons, and protons? Draw a picture of an atom from what
More informationCHEMISTRY Matter and Change. Chapter 4: The Structure of the Atom
CHEMISTRY Matter and Change Chapter 4: The Structure of the Atom CHAPTER 4 Table Of Contents Section 4.1 Section 4.2 Section 4.3 Section 4.4 Early Ideas About Matter Defining the Atom How Atoms Differ
More informationAtomic Structure and Nuclear Chemistry Multiple Choice Questions PSI Chemistry
Atomic Structure and Nuclear Chemistry Multiple Choice Questions PSI Chemistry Name: 1. What was the first particle discovered inside an atom? A. Proton C. Electron 2. What characteristic of cathode rays
More informationEarly 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 informationAtomic Models. A model uses familiar ideas to explain unfamiliar facts observed in nature. A model can be changed as new information is collected.
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 Models A model uses familiar ideas
More informationNJCTL.org 2015 AP Physics 2 Nuclear Physics
AP Physics 2 Questions 1. What particles make up the nucleus? What is the general term for them? What are those particles composed of? 2. What is the definition of the atomic number? What is its symbol?
More informationPreAP Chemistry. Unit 4 Atomic Structure, the Periodic Table, and Nuclear Radiation
PreAP Chemistry Unit 4 Atomic Structure, the Periodic Table, and Nuclear Radiation Democritus A Greek who lived ~400 BC, was the first to suggest the existence of atoms. He believed atoms to be indivisible
More informationChemistry Review Unit 1 Study Guide
1. Draw and label a Bohr model of a C 14 atom. 2. Describe the following about a proton a. mass: the mass of a proton is 1 atomic mass unit (AMU) b. charge: protons have a positive charge c. location:
More informationGeneral Chemistry Standard : Identify the significance of the various outcomes of Thomson s and Rutherford s experiments
Not the history of the atom, but the idea of the atom The atom was not discovered until recently Original Idea Ancient Greece (400 BC) Proposed by lesser-known scientists They looked at a beach made of
More informationNOTES ON CHAPTER 4: ELEMENTS AND THE PERIODIC TABLE. 4.1 Introduction to Atoms
NOTES ON CHAPTER 4: ELEMENTS AND THE PERIODIC TABLE 4.1 Introduction to Atoms The first people to think about the nature of matter were the ancient Greeks. Around 430 B.C, Democritus, a Greek philosopher,
More informationUNIT 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 informationCard 1 Chapter 18. Card 2. Chapter 18. Negative particles that surround the nucleus (like planets around the sun)
Card 1 Card 2 Positive particles in the nucleus of the atom Negative particles that surround the nucleus (like planets around the sun) Card 3 Card 4 Neutral particles in the nucleus of the atom. They help
More informationAtomic Structure. History of Atomic Theory
Atomic Structure History of Atomic Theory Democritus (460-370 BC) Was the to come up with the idea of atom Believed that all matter was composed of Which is derived from the Greek word Atomos meaning He
More informationChemistry. Robert Taggart
Chemistry Robert Taggart Table of Contents To the Student..................................................v Unit 1: Matter and Measurement Lesson 1: Chemistry and the Scientific Method...................3
More informationTHE ATOM Pearson Education, Inc.
THE ATOM Title and Highlight Right Side NOTES ONLY TN Ch 4.1-4.2 Topic: EQ: Date Reflect Question: Reflect on the material by asking a question (its not suppose to be answered from notes) NOTES: Write
More informationWhat is matter? Matter is anything that has mass and takes up space. Matter is made up of atoms.
Matter What is matter? Matter is anything that has mass and takes up space. Matter is made up of atoms. Is it matter? Can you measure the object? Does it take up space? Does the object have a mass? Come
More informationDemocritus 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 informationChapter 3 Atomic Diary
Chapter 3 Atomic Diary History of the Atom Democritus was a philosopher in ancient Greece who "thought" about things, and came up with his ideas. He thought that all kinds of matter were unique and that
More informationThe Development of Atomic Theory
The Development of Atomic Theory Ideas & Theories in Science Change Our theory about the atom has changed over time as new studies are done. Even though no one has ever seen an atom up close we are still
More informationAtomic 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 informationUNIT 2 - ATOMIC THEORY
UNIT 2 - ATOMIC THEORY VOCABULARY: Allotrope Electron Configuration Nuclear Charge Anion Element Nucleons Atom Excited state Nucleus Atomic Mass Ground state Orbital Atomic Mass unit (a.m.u.) Ion Proton
More informationChapter 4. History of the atom. History of Atom Smallest possible piece? Atomos - not to be cut. Atoms and their structure
Chapter 4 Atoms and their structure History of the atom Not the history of atom, but the idea of the atom. Original idea Ancient Greece (400 B.C.) Democritus and Leucippus Greek philosophers. Looked at
More informationCH4 HOMEWORK : ATOMIC STRUCTURE
Name Date Class 4 CH4 HOMEWORK : ATOMIC STRUCTURE SECTION 4.1 DEFINING THE ATOM (pages 101 103) This section describes early atomic theories of matter and provides ways to understand the tiny size of individual
More informationUNIT 2 - ATOMIC THEORY
*KEY* *KEY* UNIT 2 - ATOMIC THEORY *KEY* *KEY* VOCABULARY: Allotrope Anion Atom Atomic Mass Atomic Mass unit (a.m.u.) Atomic number Bohr model Cation Compound Electron Electron Configuration Element Excited
More informationNuclear Physics and Nuclear Reactions
Slide 1 / 33 Nuclear Physics and Nuclear Reactions The Nucleus Slide 2 / 33 Proton: The charge on a proton is +1.6x10-19 C. The mass of a proton is 1.6726x10-27 kg. Neutron: The neutron is neutral. The
More informationATOMIC 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 informationH CHEM - WED, 9/7/16. Do Now Be ready for notes. Sigfig review problem. Agenda Atomic Theory. Homework. Error Analysis
H CHEM - WED, 9/7/16 Do Now Be ready for notes. Sigfig review problem Agenda Atomic Theory Error Analysis Homework Possibly atomic theory paragraph THE ATOM DEFINITION TO START Atom smallest particle
More informationNuclear Physics Questions. 1. What particles make up the nucleus? What is the general term for them? What are those particles composed of?
Nuclear Physics Questions 1. What particles make up the nucleus? What is the general term for them? What are those particles composed of? 2. What is the definition of the atomic number? What is its symbol?
More informationHistory and Structure of the Atom. From Democritus to...
1 History and Structure of the Atom From Democritus to... History of Atomic Theory 2 Democritus (from about 440 BC) coined the term atom which means uncuttable He felt that if you kept cutting matter smaller
More informationPROGRESSION 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 informationTo remain valid, models and theories must:
Note Taking Guide: Episode 301 Model: A idea used to explain facts in. Theory: An of facts and. To remain valid, models and theories must: all known enable to make correct Democritus: proposed the of an
More informationPassing an electric current makes a beam appear to move from the negative to the positive end.
Chapter 4 Atoms and their structure History of the atom Not the history of atom, but the idea of the atom. Original idea Ancient Greece (400 B.C.) Democritus and Leucippus Greek philosophers. Smallest
More informationGlencoe: 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 informationEarly 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 informationThe 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 informationUNIT 13: NUCLEAR CHEMISTRY
UNIT 13: NUCLEAR CHEMISTRY REVIEW: ISOTOPE NOTATION An isotope notation is written as Z A X, where X is the element, A is the mass number (sum of protons and neutrons), and Z is the atomic number. For
More information