Chapter 2:CHE 101 Lecture Outline CHAPTER 2Chapter 2:Atoms, Molecules & IonsMATERIAL TO LEARN ON YOUR OWN I do not have time to cover Sections 2.1-2.2 & 2.5 in lecture. A Pre-recorded lecture is located on UB Learns, located: • Gulde Folder-PreRecorded Folder-Chapter02_Atom History• Gulde Folder-PreRecorded Folder-Chapter02_Periodic Table- You MUST watch the periodic table prior to next lecture!! Turn to Page 10 “Today’s Atom” of lecture NotesAtomic Theory of Matter Greek philosophers posed the questions: “Can matter be divided into smaller and smaller pieces?”  “Is there a point at which there is no more division?” Democritus (460-370 B.C.): argued matter consisted of indivisible (__________________) particles called __________________ Plato & Aristotle said there ____________________ be indivisible particles & the “Atomic” view _______________________ John Dalton (1803-1807): Brought back the _____________ concept 4 postulates which lead to 3 Atomic Theory Laws1CHE 101 Lecture Outline CHAPTER 2Dalton’s 4 Postulates1. Each element is composed of extremely small particles called ____________________2. All atoms of 1 element are _____________________, but ______________________ from the atoms of all other elements3. Atoms of 1 element ___________________________________________ into atoms of a different element by chemical reactions (rxns); atoms are neither ___________________ nor _______________________ in chemical rxns4. Compounds are formed when atoms of ________________________________ element combine in a specific _________2CHE 101 Lecture Outline CHAPTER 2John Dalton’s 3 Atomic Theory Laws1. Law of definite (constant) composition – the “relative number” (________________) & kind (_________________________) of atoms are constant (derived from postulate 4) Regardless of source, a compound is always the __________________• Carbon dioxide (CO2) from NY or NJ is the same - Both contain same type of atoms: _____________ & ___________- Both contain same ratio of atoms(____________________________________________) Mass percent  mass _________________________________ contributes in relation to the total compound mass Ex: A 20.0g sample of CO2 containing 5.44g of carbon was collected in NY, what is the masspercent of carbon? A different 34.7g sample was collected in NJ, and is believed to be CO2. It was found to have 9.44g carbon, is the second sample CO2?3CHE 101 Lecture Outline CHAPTER 2John Dalton’s 3 Atomic Theory Laws Cont’d In chemical reactions, atoms ____________________________ to form NEW chemicals2. Law of mass conservation – the total starting masses ____________________________ thetotal ending masses (derived from postulate 3) Ex: Decomposition of water:18g H2O  3. Law of multiple proportions – the __________________ of the mass ratios of 2 different compounds can be expressed as a ________________________________ Multiple atoms forms multiple compounds (H2O vs H2O2) Ex:• Compound 1: 11.2g H and 88.8g O• Compound 2: 5.9g H and 94.1g OTo find Ratio  put _____________mass ratio in numeratorCompound 1H – mass ratio:H – Ratio:Compound 2H – mass ratio:Compound ____ (b/c on top)contains ________________more Hydrogen thanCompound _______O – Ratio:Compound ____ (b/c on top)contains ________________more Oxygen than Compound_____Compound 2O – mass ratio:Compound 1O – mass ratio:4CHE 101 Lecture Outline CHAPTER 2Discovery of Electrons J.J. Thompson – (1897) : Cathode ray tube A cathode (metal) plate emits _____________________ cathode rays Rays bend ___________________ a positive & ___________________________ a negative electric field when a magnet is turned on Discovered that atoms have particles (aka_________________________) that are _______________________ charged Millikan– (1909) :Oil drop experiments Droplets of oil passed through an electrically charged plate & an X-ray source X-rays caused electrons in the air to attach to the oil drops, resulting in a ______________________ charge  Discovered that electrons:a) are ______________________ charged = 1.6x1019 C b) have a __________________ = 9.10x1028 gDiscovery of the Nucleus Thompson – Plum pudding model Atoms are ________________________• Even distribution of ___________________________________________ charges throughout the entire atom5CHE 101 Lecture Outline CHAPTER 2 Ernest Rutherford (1910) : Gold Foil Expt Aimed ______________________  radiation at sheets of gold foil• Particles should go __________________________, but some ______________________ OR _________________________________! Atoms are mostly empty space occupied by ________________________, but in the CENTER is the _____________________ that contains all the positive charge and nearly all the mass• Called the positive particles ________________________6CHE 101 Lecture Outline CHAPTER 2MATERIAL TO LEARN PRIOR TO NEXT LECTURE Video Location: Gulde Folder - PreRecorded Folder -Chapter02_Periodic TablePeriodic Table Terminology Group (family) – _______________________ Referred to by _________________ # or _________________  Period – ______________ Beware of _________________ A.K.ARare Earth – 7CHE 101 Lecture Outline CHAPTER 2Types of Elements Determined by ____________________________ line1. Metals - ___________ of line(Except: Hydrogen, Hnonmetal) _____________ at room temp (except Mercury, Hg) Properties:- Lustrous (shiny)- High conductivity (electrical & thermal) - Malleable: pounded into sheets- Ductile: drawn into wires2. Nonmetals - _____________ of line At room temp - 6 solids: C, P, S, Se, I (I2), At- 1 liquid: Br (Br2)- 11 gasses Properties:- Solids: ______ lustrous, ______ conductivity, _____ malleable nor ductile3. Metalloids (semimetals) - _____________ touching the line(Except: Aluminum, Al metal) Hves properties of ________, but more like side it is on- Te: more like _____________________b/c on __________________ side  Extremely important in chemistry! 8CHE 101 Lecture Outline CHAPTER 2 MUST be able to tell difference b/t metal & nonmetal! Chemical formulas Chemical formula - uses _________________________ & numeric _______________ to indicate the atoms in a compoundA. Molecular formula - chemical formula that indicates the ___________________ ____________________ of atoms in a molecule• Benzene =