Lecture 3 - Elements, Matter, and the Atom

Monday, January 15, 2024

11:58 AM

"Isotopes are atoms which have the same nuclear charge but different ﷟HYPERLINK "https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl"atomic weights." ﷟HYPERLINK "https://www.nobelprize.org/prizes/chemistry/1922/aston/biographical/"Francis William Aston (Biography) ﷟HYPERLINK "https://www.nobelprize.org/uploads/2018/06/aston-lecture.pdf"Francis W. Aston - Nobel Lecture 1922 - Great summary of what we will learn this week ﷟HYPERLINK "https://boisestatecanvas.instructure.com/courses/28699/discussion_topics/653829"This week's overview Assignments this week: ﷟HYPERLINK "https://boisestatecanvas.instructure.com/courses/28699/assignments/983789"Reading quiz on sections 2.1-2.6 due on Wednesday. ﷟HYPERLINK "https://boisestatecanvas.instructure.com/courses/28699/assignments/984381"Reading quiz on sections 2.7-2.12 due on Friday. ﷟HYPERLINK "https://boisestatecanvas.instructure.com/courses/28699/assignments/984554"Homework 2 (chapter 2) on Aktiv Chemistry due on Sunday Activity 1: ﷟HYPERLINK "https://boisestatecanvas.instructure.com/courses/28699/assignments/985392"Energy Source Investigation Write-up by Wednesday (1/31) (2 weeks) ﷟HYPERLINK "https://boisestatecanvas.instructure.com/courses/28699/discussion_topics/654027"Peer reviews due Sunday (2/4) (18 days away) Office Hours: Friday 11-1 CIC ﷟HYPERLINK "https://calendly.com/bricejurban/office-hours"By appointment Today's Schedule: Composition of the Universe Classifying matter Pure substances (Elements and Compounds) Mixtures (homogeneous and heterogeneous) Classifying Energy Explain Activity 1 Classifying Forces Elements Fun Facts Law of Conservation of Mass, Constant Composition, and Multiple Proportions Daltons Postulates of the Atom Atomic Mass Thursday's Schedule: Structure of the Atom Early experiments about the atom Nomenclature I Isotopic notation Ions Everything is composed of either matter or energy in ﷟HYPERLINK "https://youtu.be/u8lx19V7SNg?si=Q1W1DK9Z0ktZ4gQs"spacetime Click this link to open a wall chart called the Correlated History of Matter Includes: Timeline of Matter and Energy Earth Rocks and Minerals Meteorites and Rocks created by Impacts Periodic Table Double click this icon
Periodic Table Fundamental Particles and Forces this icon Untitled picture.png Matter and energy in toda Is Universe Dark Energy 65% Dark Matter 30% Free Hydrogen 4% and Helium Stars 0.5% Heavy Elements 0.03% Dark matter is an invisible substance thought to make up about 27% of the universe's mass, influencing the motion of galaxies and galaxy clusters, while dark energy is a mysterious force driving the accelerated expansion of the universe, comprising about 68% of the universe's total energy content. The remaining 5% of the universe is composed of ordinary, or "baryonic," matter, which includes everything that we can see, feel, and measure directly - stars, planets, galaxies, and all other forms of matter made up of atoms. This includes the energy associated with that matter. How can we classify matter? Matter makes up the substances in the universe It is anything that has mass and takes up space We classify matter in terms of how it can be separated, either by physical or chemical means. 🍎 Embedded file printout Composition of Matter_1.png ixtu Is me composition unißrrn? atte Can it pnysica'y separated based on see, Censny. or physical property'? (Fitration. OistjllaW1. Evapuatjon, Decantabon. Magnebc Separation. Centrifugation, Chromatogram Sieving. Sedimentabon. Suünation, Extracton. Precimtabon, Recrystaüzabon. etc) ure Substan Can it be Chemicay aciCf--base omel chemical reactions) s disso 14kt gold 02 58.5% Au 440 ppm C02 cu trace gases such as water 14kt 'mite vapor and ozone 58.5% 115% Ni Am a" ams (Mercury ( F -"J another meta) A a nite Substance knownas a Solute dissolved in a liWid Solvent Meture (Components or phages 'med Phase Emulsions that dont mix (Exam*- and water) SOWd that dissolve in a but remain even S (Examples. paint, bk)Od) Very rme particles dispersed another Can be solid •quid gas, etc Examples: Wk, Fog) or mue different elements Examples: Water ("20) Table san (Nacr) sucrose (C12H22011) Examples: Gold (Aul Alumnum (N) oxygen (02) Ozone (03) Nitogen (N2) (NaCl in Water) Sugar soX (Sucrose in Viegar (acetic n water)
Embedded file printout Composition of Matter_1.png ixtu Is me composition unißrrn? atte Can it pnysica'y separated based on see, Censny. or physical property'? (Fitration. OistjllaW1. Evapuatjon, Decantabon. Magnebc Separation. Centrifugation, Chromatogram Sieving. Sedimentabon. Suünation, Extracton. Precimtabon, Recrystaüzabon. etc) ure Substan Can it be Chemicay aciCf--base omel chemical reactions) s disso 14kt gold 02 58.5% Au 440 ppm C02 cu trace gases such as water 14kt 'mite vapor and ozone 58.5% 115% Ni Am a" ams (Mercury ( F -"J another meta) A a nite Substance knownas a Solute dissolved in a liWid Solvent Meture (Components or phages 'med Phase Emulsions that dont mix (Exam*- and water) SOWd that dissolve in a but remain even S (Examples. paint, bk)Od) Very rme particles dispersed another Can be solid •quid gas, etc Examples: Wk, Fog) or mue different elements Examples: Water ("20) Table san (Nacr) sucrose (C12H22011) Examples: Gold (Aul Alumnum (N) oxygen (02) Ozone (03) Nitogen (N2) (NaCl in Water) Sugar soX (Sucrose in Viegar (acetic n water) How can we classify Energy? Energy is what enables matter to move and change Embedded file printout Energy Flowchart_1.png nerg n ne nti pcwet Plants stars crams Rubber Band (Uranium) (Hydrogen) Energy can transform from one form to another The Total energy in a closed system remains constant How can we classify Forces? Forces are the interactions that dictate how energy and matter behave Embedded file printout Forces Flowchart_1.png Force between charged partides Radioactive &cay Carried by mons Carried by W, Z particles FMce 01 attr action all masses Carried by gravitons? (not yet discovered) Structure ot universe Omits of *nets Terrestrial gravity In finite range A:ts on PMbcJeS Electriciy and Magnetism Electron-proton attracbon Electron• Electron repu On Much stronger than Gravity I nMite range Attractive Ot Acts on and leptons (e.g. nuclei and electons) weaker than EM but stronger than V" short range Acts on Warks. charged leptons, and Force that binds protons and neurons Carried b/ glums Holds nucleus togemer (the glue) Very st-Mt Acts on warts. and 'uons Higgs Fie A tied that gives mass to particles through the Higgs mechanism Carried by Hiws parbcÉ Not a force but essential lot the magg 01 W and Z particleswWch carry the weak force Peter Higgs Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings
Embedded file printout Forces Flowchart_1.png Force between charged partides Radioactive &cay Carried by mons Carried by W, Z particles FMce 01 attr action all masses Carried by gravitons? (not yet discovered) Structure ot universe Omits of *nets Terrestrial gravity In finite range A:ts on PMbcJeS Electriciy and Magnetism Electron-proton attracbon Electron• Electron repu On Much stronger than Gravity I nMite range Attractive Ot Acts on and leptons (e.g. nuclei and electons) weaker than EM but stronger than V" short range Acts on Warks. charged leptons, and Force that binds protons and neurons Carried b/ glums Holds nucleus togemer (the glue) Very st-Mt Acts on warts. and 'uons Higgs Fie A tied that gives mass to particles through the Higgs mechanism Carried by Hiws parbcÉ Not a force but essential lot the magg 01 W and Z particleswWch carry the weak force Peter Higgs ﷟HYPERLINK "https://www.youtube.com/watch?v=aZLvHM_mt6Y"Neil deGrasse Tyson explains the Higgs boson particle BBC Radio 4 Neil deGrasse Tyson explains the Higgs boson particle Press enter to activate ﷟HYPERLINK "https://www.youtube.com/watch?v=cK2SVfDMMrU"The Periodic Table Song with real elements The Periodic Table Song with real elements Press enter to activate
The Periodic Table Song with real elements Press enter to activate Elements Multivitamin.JPG Amount Per Sewing Caldtrn % value 210 mg (a Camm Catbmate & Dcaäum Phosphate) 1m (a Fns Furrate) 8 mg 20 mg une (c Potassium Iodide) 150 mcg Magnæn(cMqrBitmOide) 100 mg Zrc(aZncOxjde) 11 mg Eium(aSodunSdenate) 100 mcg (a Sulfate) 0.9 mg Manganese SUfate) 2.3 mg Chromium (as Chromium Picolirnte) 35 mcg Molybdenum (as Sodium Mob,'bdate) 50 mcg Chloride@Potasin Chloride) 72 mg Potasium (as Potasium Chloride) 80 mg 2% 100% 100% 182% 100% 100% 100% 111% 3% The elements are necessary for life as we know it. There are 94 naturally occurring elements on Earth. (Hydrogen through Plutonium) 80 of these from Hydrogen (element 1) to Lead (element 82) have at least one stable isotope that does not undergo radioactive decay. (Technetium (element 43) and Promethium (element 61) are notable exceptions)
80 of these from Hydrogen (element 1) to Lead (element 82) have at least one stable isotope that does not undergo radioactive decay. (Technetium (element 43) and Promethium (element 61) are notable exceptions) The transuranium elements are synthetic and have been artificially produced through nuclear reactions. (elements with greater than 92 protons). As of now, scientists have discovered 118 elements, the last of which is element Oganesson (Og) and named after living scientist Yuri Oganessian, a Russian nuclear physicist who significantly contributed to the discovery of superheavy elements. The most recent element to be discovered was element 117 Tennessine in April 2010 (during your lifetime!) by a collaboration of Russian scientists at the Joint Institute for Nuclear Research in Dubna, Russia, and American scientists at the Oak Ridge National Laboratory in Tennessee, USA. Some elements have been known since antiquity, but the discovery of most was not an easy feat. Most elements are present in very trace amounts, and almost none are present in pure form and therefore must be isolated. The hunt for new elements has not abated. I predict that element 119 or 120 will be discovered in our lifetime and then we will have to add another row to our periodic table. That will be truly an amazing day. Is there a fundamental limit? Some physicists believe that there is an ﷟HYPERLINK "https://en.wikipedia.org/wiki/Island_of_stability"island of stability in the region of superheavy elements that would have longer half-lives. Additionally some quantum theorists believe that in the theoretical element 137, the electromagnetic radiation would compete with the nuclear force so strongly that speeds faster than the speed of light would be necessary (impossible), so the atom would be inherently unstable. Applying atomic theory we can understand the differences in the elements through their subatomic particles. The chemical properties of an element depend solely on its atomic number (Z), which is the charge on its nucleus expressed in terms of the unit charge, e. Therefore the elements are arranged 1 through 118 on the periodic table simply by the numbers of protons that they contain in their nucleus. Atomic symbols An appeal to memorize these ﷟HYPERLINK "https://quizlet.com/814496647/elemental-symbols-and-names-flash-cards/?funnelUUID=983fdaf0-ec1f-4aeb-b943-1404b11cef95"50 elements Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings The second letter must be lowercase The isotopes of hydrogen get their own letter
An appeal to memorize these ﷟HYPERLINK "https://quizlet.com/814496647/elemental-symbols-and-names-flash-cards/?funnelUUID=983fdaf0-ec1f-4aeb-b943-1404b11cef95"50 elements The three Laws that led to the Atom Law of Conservation of Mass In a chemical reaction, the total mass of the reactants is equal to the total mass of the products formed. Parents of Modern Chemistry Lavoisier_and_His_Wife.jpg Antoine Lavoisier and Marie Anne Lavoisier Law of Constant Composition (Definite Proportions) The relative amount of each element in a particular compound is always the same. Regardless of origin or preparation Untitled picture Image result for proust chemist Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings get their own letter
Law of Multiple Proportions When a given element combines with another element to form two different compounds, for a fixed mass of the first, the ratio of the two compounds consists of small whole numbers A014739_John-Dalton-founder-of-chemical-atomic-theory.jpg John Dalton, founder of chemical atomic theory stock image | Look and Learn John Dalton Daltons Postulates All matter is made of atoms that are indivisible All atoms of a given element are identical in mass and properties Atoms of different elements differ in mass and properties Compounds are formed by a combination of two or more different kinds of atoms A chemical reaction is a rearrangement of atoms, no atoms are created, destroyed, or transmuted. Atomic Masses are Relative DaltonsElements.jpg 0 O 0 0 ◎ 0 O 0 0 0 0 0 19 0 0 0 0 22 00 26 27 26 30 31 3 3 34 3 5 0 0 ' OA Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings 1/12 of 12 grams of carbon-12 Dalton misinterpreted the data. He assumed elements were only monoatomic This is not true!
DaltonsElements.jpg 0 O 0 0 ◎ 0 O 0 0 0 0 0 19 0 0 0 0 22 00 26 27 26 30 31 3 3 34 3 5 0 0 ' OA Practice Explain how you could separate table salt, NaCl(s), from sand. Add deionized (DI) water to the mixture to dissolve the salt. Decant or filter out the sand, then dry. Evaporate the water from the salt water mixture to recover the salt. A 1.28-gram sample of copper is heated with sulfur to produce 1.60 grams of a copper sulfide compound. Calculate the mass percentages of copper and sulfur in the compound. Sulfur forms two oxides. In one of them, 1.87 grams of sulfur combines with 1.87 grams of oxygen, and in the other 3.94 grams of sulfur combines with 5.91 grams of oxygen. Show how these data illustrate the law of multiple proportions. Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings Ink Drawings
sulfur + oxygen sulfur/g oxygen/g ratio sulfur:oxygen Compound 1 1.87 1.87 1.00:1.00 Compound 2 3.94 5.91 0.666:1.00 or 2.00:3.00 The simplest ratio of sulfur to oxygen in the first compound is 1:1 In the second compound if should recognize that 0.666 is ﷐𝟐﷮𝟑﷯. by multiplying the ratio by 3 it is easier to see the whole number ratio is 2:3 The first compound might have the chemical formula SO, or S2O2, or S3O3, etc. In the second compound the data suggest the formula S2O3 or higher multiples. The data indicates the ratio of the two compounds is in whole number ratios and this illustrates the law of multiple proportions. (The use of moles or atomic masses is not needed here). Suppose we decide to establish an atomic mass scale by setting the atomic mass of 12C exactly equal to one. What would be the atomic masses of naturally occurring hydrogen and oxygen on this scale? The atomic mass of 12C is normally 12.000 but in this system it is 1.000. We need to just use simple ratios to determine the new atomic masses of hydrogen and oxygen ﷐12.000﷮1.008﷯=﷐1.000﷮﷐H﷮∗﷯ amu﷯ ﷐12.000﷮16.00﷯=﷐1.000﷮﷐O﷮∗﷯ amu﷯ H* = 0.0840 amu O* = 1.333 amu Ink Drawings

 

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