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© 2012 Pearson Education, Inc. CH 4 : THE ATOM On the first right side page (after Ch 3 notes): Create a Cover page for Chapter 4. Make atom design the whole page and label the parts of the atom. Include COLOR! I have a sample one online you can use On the back side of cover page (left side), Paste in the “I can” Learning Objectives #10-22.

CH 4 : THE ATOM - Chemistry · 2019. 10. 24. · NUCLEUS OF AN ATOM •Nucleus- VERY small region located at the center of the atom. The nucleus accounts for most of an atoms mass

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  • © 2012 Pearson Education, Inc.

    CH 4 : THE ATOM

    On the first right side page (after Ch 3 notes):

    • Create a Cover page for Chapter 4.

    • Make atom design the whole page and label the

    parts of the atom.

    • Include COLOR!

    • I have a sample one online you can use

    On the back side of cover page (left side),

    • Paste in the “I can” Learning Objectives #10-22.

  • © 2012 Pearson Education, Inc.

    TN Ch 4.1 Date

    Title and

    Highlight

    Topic:

    EQ:

    NOTES:

    Write out the notes from my website.

    Use different types of note-taking

    methods to help you recall info (different

    color pens/highlighters, bullets, etc)

    When I lecture we will add more info, so

    leave spaces in your notes

    Summary Questions:

    2-3 sentences… What did you learn

    today from the notes?

    THESE ARE AT THE VERY END OF

    NOTES

    Right Side – NOTES ONLY

    Reflect

    Question:

    Reflect on

    the

    material by

    asking a

    question

    (its not

    suppose to

    be

    answered

    from

    notes)

  • © 2012 Pearson Education, Inc.

    TN Ch 4.1

    Title and

    Highlight

    DRAW ANY PICTURES, FIGURES,

    AND WRITE OUT ANY PRACTICE

    PROBLEMS/QUESTIONS.

    WE WILL ANSWER THEM TOGETHER.

    LEAVE SPACES SO WE CAN ANSWER

    QUES.

    LEFT Side – PICTURES, PRACTICE PROBLEMS, ETC

  • © 2012 Pearson Education, Inc.

    TOPIC: ATOMIC THEORY

    EQ: Explain the history & the discovery of the atom

    Ch 4.1-4.2

    READ Ch 4.1-4.2 (pg. 93-95) first then write notes

  • © 2012 Pearson Education, Inc.

    CH 4.1 ATOMS • Atoms are incredibly small.

    • To get an idea of how small atoms are: • if every atom within a small pebble were the size

    of the pebble itself, the pebble would be larger than Mount Everest.

  • © 2012 Pearson Education, Inc.

    ATOMS AND ELEMENTS• ATOM - “Building Blocks of Matter”• An atom is the smallest particle of an element that retains the chemical properties of that element.

    • An element is a substance that cannot be broken down into simpler substances.

    • There are about 91 different elements in nature, and consequently about 91 different kinds of atoms. (The other 27 are synthetic – man made elements)

  • © 2012 Pearson Education, Inc.

    CH 4.2

    The Atom: From Philosophical Idea to Scientific Theory

  • © 2012 Pearson Education, Inc.

    THE EARLY ATOM

    • As early as 400 B.C., Democritus called nature’s basic particle the “atomon” based on the Greek word meaning “indivisible”.

    • His theory: Matter could not be divided into smaller pieces forever, eventually the smallest possible piece would be obtained.

  • © 2012 Pearson Education, Inc.

    ATOMS

    ▪To Democritus, atoms were small, hard particles that were all made of the same material but were different shapes and sizes.

    ▪Atoms were infinite in number, always moving and capable of bonding together.

  • © 2012 Pearson Education, Inc.

    THE EARLY ATOM

    • Most influential philosopher, Aristotle rejected Democritus’ atom theory b/c different from his ideas

    • Criticized Democritus’ idea that atoms moved through empty space

    • Aristotle succeeded Democritus and did not believe in atoms. Instead, he thought that all matter was continuous. It was his theory that was accepted for the next 2000 years.

  • © 2012 Pearson Education, Inc.

    WHY?

    • In the end….. Aristotle was wrong in the end.

    Aristotle favored

    the earth, fire, air

    and water

    approach to the

    nature of matter.

  • © 2012 Pearson Education, Inc.

    DALTON’S ATOMIC THEORY• John Dalton (1766-1844)

    • English Chemist and schoolteacher

    • In 1808,performed a number of experiments that led to the idea of atoms…..over 2000 years later after Democritus/Aristotle theory.

    I was a

    school

    teacher at

    the age of

    12!

  • © 2012 Pearson Education, Inc.

    DALTON’S ATOMIC THEORY

    1. All matter is composed of extremely small particles called atoms.

    2. Atoms of a given element are identical in size, mass, and other properties.**

    3. Atoms cannot be subdivided, created, or destroyed.**

    4. Atoms of different elements combine in simple whole-number ratios to form chemical compounds.

    5. In chemical reactions, atoms are combined, separated, or rearranged.

    **Today, we know these parts to be wrong!!

    http://tm.ask.com/r?t=c&s=p&sv=0a30052b&uid=0BC1ACC9982C64134&sid=3444474eb444474eb&o=0&id=30751&p=/fr&u=http://www.juliantrubin.com/imagesc/dalton1.gif

  • © 2012 Pearson Education, Inc.

    • Was Dalton’s theory a huge step toward our current model of matter?

    • Yes!!! It was a breakthrough in our understanding of matter.

    • Was all of Dalton’s theory accurate?

    • No!!!

    Dalton’s Atomic Theory

  • © 2012 Pearson Education, Inc.

    FLAWS OF DALTON’S THEORY…

    #2. Atoms of a given element are identical in size, mass, and other properties.

    #3. Atoms cannot be subdivided, created, or destroyed.

    Isotopes – atoms with the same

    number of protons but a different

    number of neutrons

    Subatomic particles – electrons,

    protons, neutrons, and more

  • © 2012 Pearson Education, Inc.

    SUMMARY:

    Let’s reflect….

    What did you learn today from the notes?

    (2-3 sentences)

    RIGHT side - THESE ARE AT THE VERY END OF NOTES

  • © 2012 Pearson Education, Inc.

    TOPIC: SUBATOMIC PARTICLES

    EQ: Explain the history & the discovery of the 3 subatomic particles in an atom

    Ch 4.3

    READ Ch 4.3 (pg. 95-97) first then write notes

  • © 2012 Pearson Education, Inc.

    CH 4.3 - DISCOVERY OF THE SUBATOMIC PARTICLES

    • The discovery of the subatomic particles came about from the study of electricity & matter.

    • Benjamin Franklin’s kite experiment in 1752 demonstrated that lightning was electrical.

  • © 2012 Pearson Education, Inc.

    DISCOVERY OF THE ELECTRON

    • 1870’s - many experiments were performed in which electric current was passed through gases at low pressures

    • These experiments were carried out in glass tubes called cathode-ray tubes.

  • © 2012 Pearson Education, Inc.

    Electric CurrentElectric Current

    Draw this with

    notes in color!!!

  • © 2012 Pearson Education, Inc.

    DISCOVERY OF THE ELECTRON

    • The rays traveled from cathode (negative) to anode (positive).

    • Negatively charged objects deflected the rays away.

    • Therefore, it was determined that the particles making up the cathode rays were negatively charged.

    http://tm.ask.com/r?t=an&s=p&uid=0BC1ACC9982C64134&sid=3444474eb444474eb&o=0&qid=76FE87617A9172D61596A95907E4D87D&io=4&sv=0a300518&ask=crookes+tube&uip=444474eb&en=is&eo=&pt=&ac=24&qs=31&pg=2&u=http://web.ask.com/fr?q%3Dcrookes%2Btube%26desturi%3Dhttp://www.ihep.ac.cn/kejiyuandi/zhishi/green/green-index.htm%26fm%3Di%26ftURI%3Dhttp://pictures.ask.com:80/fr?q%3Dcrookes%2Btube%26desturi%3Dhttp://www.ihep.ac.cn/kejiyuandi/zhishi/green/green-index.htm%26imagesrc%3Dhttp://www.ihep.ac.cn/kejiyuandi/zhishi/green/crookes-tube_small.jpg%26thumbsrc%3Dhttp://images.picsearch.com/is?7001082979393%26thumbwidth%3D128%26thumbheight%3D71%26fn%3Dcrookes-tube_small.jpg%26f%3D2%26fm%3Di%26ftbURI%3Dhttp%3A%2F%2Fpictures.ask.com%2Fpictures%3Fq%3Dcrookes%2Btube%26page%3D2%26qt%3D0

  • © 2012 Pearson Education, Inc.

  • © 2012 Pearson Education, Inc.

    THOMSON’S PLUM PUDDING MODEL

    • In 1897, the English scientist J.J. Thomson provided the first hint that an atom is made of even smaller particles.

    (1908 Nobel Prize in Chemistry)

  • © 2012 Pearson Education, Inc.

    THOMSON’S PLUM PUDDING ATOMIC MODEL

    Thomson believed that the electrons were like plums

    embedded in a positively charged “pudding,” thus it

    was called the “plum pudding” model.

    Draw this with

    notes in color!!!

  • © 2012 Pearson Education, Inc.

    • So….. J. J. Thomson discovered the electron.

    • found that e- are negatively charged.

    • e- are much smaller and lighter than atoms.

    • every element (atom) has e-.

    • He proposed that atoms must contain + charge that balanced the - charge of electrons.

  • © 2012 Pearson Education, Inc.

    Millikan’s Oil Drop

    Experiment

    Robert Millikan (1909): Millikan’s Oil-drop ExperimentDiscovered the mass and charge on the electronCharge of electron: -1

    Mass of electron = 9.1 x 10-28 g

    004_MILLIKANOIL.MOV004_MILLIKANOIL.MOVfile:///C:/1213 School Year/Honors Chemistry/Chapter 2 Atoms Molecules Ions/flash shockwave animations/02_Millikan_Oil_Drop.swf

  • © 2012 Pearson Education, Inc.

    RUTHERFORD’S GOLD FOIL EXPERIMENT• 1911 - English

    physicist Ernest Rutherford

    • Rutherford’s experiment involved firing a stream of tiny positively charged alphaparticles at a thin sheet of gold foil(2000 atoms thick)

  • © 2012 Pearson Education, Inc.

    RUTHERFORD’S FINDINGS• Most of the positively

    charged particles passed through the gold foil without changing course.

    • Some of the positively charged particles did bounce away from the gold sheet as if they had hit something solid.

    Draw this with

    notes in color!!!

  • © 2012 Pearson Education, Inc.

    (1) Most of the atom is more or less ______ _______.

    (2) The nucleus is very _________ and ___________.

    (3) The nucleus is ______________ charged due to protons.

    (4) The nucleus (protons and neutrons) is 99.97% of an atom’s mass.

    (5) The electron cloud = majority of volume

    • SO……. atoms is neutral: the positive (nucleus) balances out the negative electrons

    • So, why do electrons stay surrounded around the nucleus?

    “Opposites attract”

    empty space

    densetiny

    positively

  • © 2012 Pearson Education, Inc.

    A SUMMARY OF THE NATURE OF ELECTRICAL CHARGE•Positive and negative

    electrical charges attracteach other.

    •Positive–positive and negative–negative charges repel each other.

    •Positive and negative charges cancel each other so that a proton and an electron, when paired, are charge-neutral.

    Draw this with

    notes in color!!!

  • © 2012 Pearson Education, Inc.

    Rutherford’s Model of

    the Atom

    2.2

    Draw this with

    notes!!!

  • © 2012 Pearson Education, Inc.

    James Chadwick (1932)

    Discovered the neutron.

    The neutron has about the same mass as

    the proton.

  • © 2012 Pearson Education, Inc.

    • After the proton & electron was discovered….

    • The Neutron was discovered last (almost 30 years later) out of all the subatomic particles, why?

    • Scientist knew the charge of nucleus (+) and knew the mass of nucleus (came from proton). But their calculations were off by half…. could not figure out why the nucleus was so heavy if the proton only had a certain mass.

    • There must be a third subatomic particle that weighed as much as a proton, but with no charge!

  • © 2012 Pearson Education, Inc.

    Democristus

    400BC

    Aristotle

    4 elements

    Dalton (1803)

    Atomic Theory

    Thomson (1897)

    Plum Pudding Model

    Cathode Ray Tube

    electrons

    Rutherford (1911)

    Gold Foil Experiment

    Proton & Nucleus (Mass and Volume)

    Millikan (1909)

    Charge & Mass

    of electron

    Chadwick (1932)

    Neutron

    THE ATOM - TIMELINE Draw this left side!!!

  • © 2012 Pearson Education, Inc.

    SUMMARY:

    Let’s reflect….

    What did you learn today from the notes?

    (2-3 sentences)

    RIGHT side - THESE ARE AT THE VERY END OF NOTES

  • © 2012 Pearson Education, Inc.

    TOPIC: THE STRUCTURE OF THE ATOM

    EQ: What is the difference between protons, neutrons, and electrons?

    Ch 4.4

    READ Ch 4.4 (pg. 97-99) first then write notes

  • © 2012 Pearson Education, Inc.

    THE ATOM

    • Atom - the smallest particle of an element.

    • How small is an atom?

    • Copper atoms in penny –29,000,000,000,000,000,000,000 (2.9 x 1022)

    Copper

  • © 2012 Pearson Education, Inc.

    THE STRUCTURE OF THE ATOM

    • The atom is composed of two main regions: the nucleus & the electron cloud.

  • © 2012 Pearson Education, Inc.

    THE ATOM

    • The atom is made up of three subatomic particles.

    Draw this with

    notes in

    color!!!

  • © 2012 Pearson Education, Inc.

    NUCLEUS OF AN ATOM

    • Nucleus- VERY small region located at the center of the atom. The nucleus accounts for most of an atoms mass but very little volume, making it a very dense region.

    • The nucleus contains protons & neutrons.

    proton = p+ neutron = no

  • © 2012 Pearson Education, Inc.

    ELECTRON CLOUD OF AN ATOM

    • The electron cloud is the negatively charged region of the atom that accounts for most of the atom’s volume but very little of the atom’s mass.

    electron = e-

    The electron cloud is

    composed of electrons.

  • © 2012 Pearson Education, Inc.

    SUBATOMIC PARTICLESParticle Symbol Location Electrical

    charge

    Mass

    (amu)

    Actual

    Mass (g)

    Electron e- Outside

    nucleus

    -1 1/1840 9.11x10-28

    (About 2000

    times smaller

    than Proton

    and neutron)

    Proton p+ Nucleus +1 1

    1.67x10-24

    Neutron n0 nucleus 0 1

    1.67x10-24

    They have the SAME Mass

    Draw this left

    side!!!

  • © 2012 Pearson Education, Inc.

    PRACTICE PROBLEMS #1

    ❑ What are the two main regions of the atom?

    ❑What is the charge on the nucleus?

    left side!!!

  • © 2012 Pearson Education, Inc.

    SUMMARY:

    Let’s reflect….

    What did you learn today from the notes?

    (2-3 sentences)

    RIGHT side - THESE ARE AT THE VERY END OF NOTES

  • © 2012 Pearson Education, Inc.

    TOPIC: ELEMENT NAMES, SYMBOLS, & THE STRUCTURE OF THE ATOM

    EQ: How do you write an element’s symbol? How many p+, no, & e- does

    any element have?

    Ch 4.5

    READ Ch 4.5 (pg. 99-101) first then write notes

  • © 2012 Pearson Education, Inc.

    CH 4.5: CHEMICAL SYMBOLS• Chemists use chemical symbols to represent elements.

    • The chemical symbol consists of 1 or 2 letters.

    • The first letter ALWAYS ______________.

    • The next letter is _______________.

    capitalized

    lowercase

  • © 2012 Pearson Education, Inc.

    CH 4.5 ELEMENTS: ORIGINS OF THE NAMES OF THE ELEMENTS

    • Most chemical symbols are based on the English name of the element.

    • Some symbols are based on Greek or Latin names, which include the following:

    potassium K kaliumsodium Na natriumlead Pb plumbummercury Hg hydrargyrumiron Fe ferrumsilver Ag argentumtin Sn stannumcopper Cu cuprum

  • © 2012 Pearson Education, Inc.

    JUST READ!!!!• Early scientists gave newly discovered

    elements names that reflected their properties:

    • Argon, from the Greek argos, means “inactive,” referring to argon’s chemical inertness.

    • Other elements were named after countries:

    • Polonium after Poland • Francium after France• Americium after the United States of

    America.

    • Other elements were named after scientists. • Curium after Marie Curie• Einstenium after Albert Einsten

  • © 2012 Pearson Education, Inc.

    THE PERIODIC TABLE OF THE ELEMENTS LISTS ALL KNOWN ELEMENTS ACCORDING TO THEIR ATOMIC

    NUMBERS.

  • © 2012 Pearson Education, Inc.

    • The # of protons in the nucleus of an atom that identifies an element.

    • The # of protons in the nucleus of an atom is its atomic number.

  • © 2012 Pearson Education, Inc.

    SYMBOL NOTATION

    XMass

    number

    Atomic

    numberSubscript →

    Superscript →

  • © 2012 Pearson Education, Inc.

    Atomic number (Z).

    Protons determines the identity of the element.

    A# = p+ = e- (atoms are neutral)

    The Mass Number (A),

    (rounded to the nearest

    integer)

    Mass# = p+ + no

    A is always the largernumber than Z.

    # of neutrons = mass number – # p+

  • © 2012 Pearson Education, Inc.

    LOOK FOR THE ELEMENT CHLORINE…..

    LET’S WRITE HIS CHEMICAL SYMBOL

    NOTATION

  • © 2012 Pearson Education, Inc.

    Cl35

    17

    MASS

    NUMBER

    ATOMIC

    NUMBER

    NUMBER OF

    PROTONS

    # PROTONS+

    # NEUTRONS

    Symbol notation

  • © 2012 Pearson Education, Inc.

    LOOK FOR THE ELEMENT CARBON…..

    LET’S WRITE HIS CHEMICAL SYMBOL

    NOTATION

  • © 2012 Pearson Education, Inc.

    SYMBOL NOTATION

    Element followed by a hyphen – mass#

    Carbon-12

  • © 2012 Pearson Education, Inc.

    • Difference between Mass and Atomic weight

    • Atomic weight is the weight of all the isotopes for that element (decimal #)

    • Mass number is the rounded number for the atomic weight.

    • Example: Copper

    • Atomic weight – 63.546

    • Mass number - 63

  • © 2012 Pearson Education, Inc.

    PRACTICE PROBLEMS

    Element Atomic

    #

    Mass

    #

    p + n o e - Symbol

    Oxygen - 8

    33 42

    -31 31 15

    91 140

    Sodium - 23

    Uranium - 238

    80

    Br

    35

    26

    Mass number

    left side

  • © 2012 Pearson Education, Inc.

    SUMMARY:

    Let’s reflect….

    What did you learn today from the notes?

    (2-3 sentences)

    RIGHT side - THESE ARE AT THE VERY END OF NOTES

  • © 2012 Pearson Education, Inc.

    TOPIC: ISOTOPES

    EQ: What is an isotope and how does it affect the atom?

    Ch 4.8

    READ Ch 4.8 (pg. 109-111) first then write notes

  • © 2012 Pearson Education, Inc.

    4.8 ISOTOPES: WHEN THE NUMBER OF NEUTRONS

    VARIES

    • All atoms of an element have the same # of protons.

    • They do not have the same # of neutrons.

    • Atoms with the same # of protons but different # of neutrons are called isotopes.

    • Example Hydrogen

  • © 2012 Pearson Education, Inc.

    ISOTOPES

  • © 2012 Pearson Education, Inc.

    EXAMPLE OF AN ISOTOPE

    Cl35

    17 Cl37

    17

    20 NEUTRONS

    ATOMIC MASS

    18 NEUTRONS

    ATOMIC NUMBER

  • © 2012 Pearson Education, Inc.

    Review…. How to write Symbol Notation

  • © 2012 Pearson Education, Inc.

    Practice Problem #1

    Circle which of the following are isotopes.

    40

    20 X40

    18 X42

    20 X40

    19 X43

    20 X

    left side!!!

  • © 2012 Pearson Education, Inc.

    Practice Problem #2

    Determine the number of protons, neutrons and electrons in the neutral (non-charged) isotopes of the following atoms:

    88

    38 Sr84

    38 Sr

    left side!!!

  • © 2012 Pearson Education, Inc.

    SUMMARY:

    Let’s reflect….

    What did you learn today from the notes?

    (2-3 sentences)

    RIGHT side - THESE ARE AT THE VERY END OF NOTES

  • © 2012 Pearson Education, Inc.

    TOPIC: AVERAGE ATOMIC MASS

    EQ: How do you calculate average atomic mass?

    Ch 4.9

    READ Ch 4.9 (pg. 111-113) first then write notes

  • © 2012 Pearson Education, Inc.

    Average Atomic Mass

  • © 2012 Pearson Education, Inc.

    • The atomic masses listed in the Periodic Table are a “weighted average” of all the isotopes of the element.

    • Units = atomic mass unit (amu)

  • © 2012 Pearson Education, Inc.

    In general, atomic mass is calculated according to the following equation:

    Average Atomic mass =

    Step 1: Convert the percent natural abundances into decimal form by dividing by 100.

    Step 2: Multiply the decimal abundances with the isotopes mass.

    Step 3: Add up the atomic masses for each isotope. This is the average atomic mass for that element (should be close to the number listed on P.T.)

  • © 2012 Pearson Education, Inc.

    • All elements have their own unique percent natural abundance of isotopes.

    • Naturally occurring chlorine consists of

    75.77% chlorine-35 (mass 34.97 amu) and 24.23% chlorine-37 (mass 36.97 amu).

    • Which isotope is the most abundant?

    • What is the Average Atomic Mass of Cl?

  • © 2012 Pearson Education, Inc.

    • Gallium has two naturally occurring isotopes: Ga-69, with mass 68.9256 amu and a natural abundance of 60.11%, and Ga-71, with mass 70.9247 amu and a natural abundance of 39.89%. Calculate the atomic mass of gallium.

    Left side: Leave 5 lines of space to solve in class

  • © 2012 Pearson Education, Inc.

    • Write Question #97 from textbook

    Left side: Leave 5 lines of space to solve in class

  • © 2012 Pearson Education, Inc.

    SUMMARY:

    Let’s reflect….

    What did you learn today from the notes?

    (2-3 sentences)

    RIGHT side - THESE ARE AT THE VERY END OF NOTES