AP Ch2: Atoms, Molecules and ions
History of Chemistry 400 B.C: Democritus (greek philosopher) hypothesizes that all matter is composed of tiny particles called atoms.
Atoms vs Hyle
1500’s: Georg Bauer-Germany, develops systematic metallurgy 1500’s: Georg Bauer-Germany, develops systematic metallurgy. How to extract metals from raw ore.
Robert Boyle-1st true chemist Wrote: The Skeptical Chymist Developed P1V1 = P2V2 Boyle’s Law
Joseph Priestly 1700’s: English clergyman discovers oxygen!
Priestly ROCKS!
Antoine Lavoisier 1700’s: French chemist, uses combustion reaction to verify the law of conservation of mass, mass cannot be created nor destroyed by ordinary chemical reactions.
Joseph Proust Proust’s Law: “The Law of Definite Proportions: A given compound always contains exactly the same proportions of elements by mass” Example: CuCO3 is always 51% Cu, 10% C and 39% O, by mass.
John Dalton….THE MAN!
John Dalton 1 Formulates the law of multiple proportions: Elements can combine to form a series of compounds. Example: N2O dinitrogen monoxide N + O2 NO nitrogen monoxide NO2 nitrogen dioxide NO1/2 cannot form
John Dalton 2 Formulates Atomic Theory: Each element is made up of tiny particles called atoms. The atoms of a given element are identical. Chemical compounds are formed when atoms come together, in simple whole number ratios. Chemical reactions involve the reorganization of the atoms; combined, separated or rearranged.
1808: Gay-Lussac Develops: P1/T1 = P2/T2
1903: J.J. THOMSON Discovers the electron, using his famous Cathode Ray Tube (CRT), which turns out to be a primitive TV or computer monitor. He also calculated the charge of electron to be -1.76 x 108 Coulombs per gram.
1909 Millikan finds the charge of an electron. Robert Millikan finds the charge on the electron to be -1.6 x 10-19 Coulombs
Robert Millikan’s Oil Drop Experiment
CRT and TV
1900’s Eugene Goldstein discovers that beams of particles travel in the opposite direction as cathode rays. These particles are protons.
1911 Ernest Rutherford Rutherford discovers the nucleus of an atom, using his famous gold foil experiment. His native New Zealand put his image on money.
Rutherford’s Gold Foil Experiment
Rutherford’s Gold Foil Experiment
James Chadwick Chadwick, Rutherford’s assistant, later made the observation that when gold nuclei are radiated with alpha particles, they sometimes emit particles, which are not affected by a charge. This was the discovery of the neutron.
Nuclear Radiation Type symbol make-up mass penetrating power Alpha a 2p+ & 2no 4 amu low Beta B high speed 1/1840 amu medium electron Gamma g high energy 0 amu high photon Positron e+ beta antiparticle 1/1840 amu high
Penetrating Power
Periodic Table: The Basics
Classes of elements to know: Group 1: Alkali metals Group 2: Alkaline-earth metals Groups 3-12: Transition Metals B, Si, As, Te, Ge, Sb are metalloids Group 17: Halogens Group 18: Noble Gases Elements #57-70: Rare-Earth Metals Elements #89-102: Radioactive Series *All elements with an atomic number greater than 83 and Tc have all radioactive isotopes. **All elements on the periodic table on the wall which are outlined are synthetic.
Nomenclature: Naming Chemical Compounds The types of chemical compounds you need to know for this chapter: Covalent binary Ionic binary A) singlevalent cation (s-block) B) multivalent cation (transition metal) Ionic ternary (containing a polyatomic ion) Ionic ternary hydrates Acids
Binary Covalent: prefix___ prefix___ + ide (2 nonmetals) # of atoms prefix examples 1 mono- CO2 2 di- CCl4 3 tri- NO2 4 tetra- N2O5 5 pent- P2O3 6 hex- SO3 7 hept- SO2
Binary ionic: cation anion+ide (metal + nonmetal) Formula Name KCl magnesium chloride NaBr lithium oxide Al2O3 calcium sulfide BeF2 strontium nitride NaH
Ionic w/ a multi-valent(transition metal) cation The oxidation number of the cation is always given in roman numerals, in parethesis. Common cations to memorize: Cr 2+ = chromium (II) aka: chromous Cr 3+ = chromium (III) aka: chromic Fe 2+ = iron (II) aka: ferrous Fe 3+ = iron (III) aka: ferric Co 2+ = cobalt (II) Co 3+ = cobalt (III) Ni 2+ = nickel (II) Ni 3+ = nickel (III) Cu + = copper (I) aka: cuprous Cu 2+ = copper (II) aka: cupric Sn 2+ = tin (II) aka stannous Sn 4+ = tin (IV) aka stannic Pb 2+ = lead (II) aka plumbous Pb 4+ = lead (II) aka plumbic Indicates the most common form
Hydrates: Name ionic compound + _______ hydrate (prefix) Example: CuSO4 . 5 H2O copper (II) sulfate pentahydrate
Acids Binary acids = hydro-_____-ic acid Ternary acids(oxyacids): Name anion, ite = ous acid OR Name anion, ate = ic acid
POP QUIZ!!!!! Name the following compounds: Na2S Fe(NO3)3 Mg(C2H3O2)2 NH4NO2 K2CO3 S2O5 CuCl Zn(ClO3)2 CuCl2 Zn(ClO4)2 CuCl2.3H2O Zn(ClO2)2 H2CO3 Zn(ClO)2 N2O3 HCl HClO2 HClO4 HClO3
END OF CHAPTER 2