Periodicity and Nomenclature “...I have tried to base a system on the magnitudes of the atomic weights of the elements. My first attempt in this respect was the following: I chose the smallest atomic weights and arranged them according to the sizes of their atomic weights. This showed that there existed a periodicity in the properties of these simple substances and that even according to their atomicity [valence] the elements followed one another in the arithmetical sequence of their atomic weights.“ Dimitri Ivanovich Mcndeleyev (Mendeleev), 1869 online 8 am labs begin at 9 am LAB REPORTS due next week (1 week after lab) include prelab again myuic.edu, Excel, LibreOffice quiz next Friday in discussion
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Periodicity and Nomenclature“...I have tried to base a system on the magnitudes of the atomic weights of the elements. My firstattempt in this respect was the following: I chose the smallest atomic weights and arranged themaccording to the sizes of their atomic weights. This showed that there existed a periodicity in theproperties of these simple substances and that even according to their atomicity [valence] theelements followed one another in the arithmetical sequence of their atomic weights.“
Dimitri Ivanovich Mcndeleyev (Mendeleev), 1869
online 8 am labs begin at 9 am
LAB REPORTSdue next week (1 week after lab)include prelab again
myuic.edu, Excel, LibreOffice
quiz next Friday in discussion
Law of Multiple ProportionsEX 3. Chlorine (Cl) and oxygen form four different binary compounds. Analysis gives the following resultsa) Show that the law of multiple proportions holds for these compounds.
cmpd mass O combined with 1.0000 g ClA 0.22564 g B/A = 0.90255/0.22564 = 3.9999... = 4B 0.90255 C/A = 1.3539/0.22564 = 5.9998... = 6C 1.3539 D/A = 1.5795/0.22564 = 7.0000... = 7 D 1.5795
b) If the formula of compound A is a multiple of Cl2O, then determine the formulas of the other compounds.
When two elements form a series of compounds the massesof one element that combine with a fixed mass of the otherelement are in the ratio of small integers to each other
law of multiple proportions is based on mole ratios
REVIEW FROM WEDNESDAY
Atomic Theory 1803 – Dalton’s Atomic Theory
all matter consists of individual atomsatoms are indestructibleall atoms of the same element are identicaldifferent elements have different kinds of atomscompounds formed from elements combining in small whole-number ratios
1808 - Guy-Lussac: gases (same T, P) combine in simple whole number ratios
1811 - Avogadro's Hypothesis - equal V (gas; same T, P)contain equal number of particles
PV = nRT => n = PV/RT
Avogadro’s law corrected Dalton’s flaw and showedthat many gases exist as diatomics
1860 - Cannizzaro: experiments convinced world that Avogadro was correct
REVIEW FROM WEDNESDAY
Building Blocks of Atoms electrons, protons, neutrons (electrons and quarks!)
gas in chamber ionized, e−’s produced adhere to droplets
gravity ↓ electric field (− → +) ↑
FIG I. 1897 – Thomson: charge/mass of e-
(Plum Pudding Model, e− + cloud of charge)
FIG II. 1909 – Mulikan:charge (oil drop exp)
FIG III. 1909 – Geiger/Marsden (α off Au) 24He2+
(nuclear model – V, e−; m small + nucleus) 1898 – Rutherford discovered α, β (1908 Nobel)
particle charge atomic mass units (amu)electron ˗1 0.000548579911proton +1 1.0072764669neutron 0 1.0086649158
Basics of the Atomsmall, dense world – example of an atom of gold diameter of a nucleus, 10-15 m diameter of an atom, 10-10 mdensity of 2.3 × 1014 g cm-3
designation
Z = atomic number (number of protons)A = mass number (sum of the numbers of protons and neutrons) – there can be isotopes
differ in number of neutrons
leptons (e.g., electrons) and quarks arethe true elementary particles of matter
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe85.468 87.62 88.906 91.22 92.906 495.95 (97/8) 101.1 102.91 106.42 107.87 112.41 114.82 118.71 121.76 127.6 126.90 131.29
55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
americium Am hassium Hs praseodymium PrANTIMONY Sb HELIUM He promethium PmARGON Ar holmium Ho protactinium PaARSENIC As HYDROGEN H RADIUM Raastatine At indium In RADON RnBARIUM Ba IODINE I rhenium Reberkelium Bk iridium Ir rhodium RhBERYLLIUM Be IRON Fe roentgenium RgBISMUTH Bi KRYPTON Kr RUBIDIUM Rbbohrium Bh LANTHANUM La ruthenium RuBORON B lawrencium Lr rutherfordium RfBROMINE Br LEAD Pb samarium SaCADMIUM Cd LITHIUM Li scandium ScCALCIUM Ca livermorium Lv seaborgium Sgcalifornium Cf lutetium Lu SELENIUM SeCARBON C MAGNESIUM Mg SILICON Sicerium Ce MANGANESE Mn SILVER AgCESIUM Cs meitnerium Mt SODIUM NaCHLORINE Cl mendelevium Md STRONTIUM SrCHROMIUM Cr MERCURY Hg SULFUR SCOBALT Co molybdenum Mo tantalum Tacopernecium Cn moscovium Mc technetium TcCOPPER Cu neodymium Nd TELLURIUM Tecurium Cm NEON Ne tennessine Tsdarmstadtium Ds neptunium Np terbium Tbdubnium Db NICKEL Ni thallium Tldysprosium Dy nihonium Nh thorium Theinsteinium Es niobium Nb thulium Tmerbium Er NITROGEN N TIN Sneuropium Eu nobelium No titanium Tifermium Fm oganesson Og TUNGSTEN Wflevorium Fl osmium Os URANIUM UFLUORINE F OXYGEN O vanadium Vfrancium Fr palladium Pd XENON Xegadolinium Gd PHOSPHORUS P ytterbium Ybgallium Ga PLATINUM Pt yttrium Yrgermanium Ge PLUTONIUM Pu ZINC Zn
zirconium Zr
H HeLi Be B C N O F NeNa Mg Al Si P S Cl ArK Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br KrRb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I XeCs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At RnFr Ra Ac Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb LuTh Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
Seven oldest known metalsNot modernSpellingMost common ending: __iumFew have ending: __um
Comment:The number of positivecharges is not indicated inthe name because it isnot necessary, e.g.,Group I elements (1+)and Group II elements(2+).
Rule:a) Newer rule: positive
charges indicated by aroman numeral.
Examples:Fe2+ iron(II) ionFe3+ iron(III) ionCu+ copper(I) ionCu2+ copper(II) ion
b) Older rule (but still used):Latin stem for the element+ "ous" for the lessercharge and + "ic" for thegreater charge. (We willuse newer rule exceptcoordination compounds)
Examples:Fe2+ ferrous ionFe3+ ferric ion
Rule:Special cases.
Examples:NH 4
+ ammonium ionH3O+ hydronium ionHg2
2+ mercury(I) ion
Comment:Hg2
2+ is Hg+ ̶ Hg+ butHg+ does not exist,therefore mercury(I) ionis Hg+. (Hg2+ is mer-cury(II) ion, but that is amonatomic ion.)
Positive Ions (Cations)
know these oxidation states
1B 2B
Monatomic Oxyanions (Containing Oxygen) Others and Exceptions(Without Hydrogen) Containing Hydrogen
Rule:Stem of the element name+ "ide".
Examples: H¯ hydride ion F¯ fluoride ion O2- oxide ion N3- nitride ion
Comment:The name does not indicatethe numbers of cations andanions because there isonly one possibility for theions to combine to form acompound.
Rule:a) Less electronegative ele-ment generally first (excep-tion: when one of the ele-ments is hydrogen)b) Greek prefixes give num-ber of atoms of each kindc) Initial prefix mono dropped
Comment:(a) These H-containingcompounds are named as ifthey were ionic. (b) Oftenthe (aq) in the formulas ofthe acids is omitted when itis obvious from the contextthat they are acids.
Rule 1:(without the presence of H2O)like ionic compounds:
ordering of elements in formulaof binary molecular compounds:order according to Groupnumber, bottom to top; for anypair, element furthest rightbehaves as the “anion” (H, Oneed to be memorized):
Compounds (Metalloid Can Be Substituted for Nonmetal)