Steps of Scientific Method
Experimental variables ?
What does experiment do?
Scientific Theory vs. Law?
Chpt 2 - Atoms, Molecules and Ions
• Atomic Theory - Greeks and Dalton• Advances in theory (Sci Method works)
– Thomson http://www.youtube.com/watch?v=IdTxGJjA4Jw&feature=related
– Millikan http://www.youtube.com/watch?v=XMfYHag7Liw
– Rutherford http://www.youtube.com/watch?v=5pZj0u_XMbc&feature=related
– Chadwick http://www.youtube.com/watch?v=oKM8uJrcmyk&feature=related
• Molecules and Ions• Periodic Table - design, group names
J J Thomson
• Postulated the existence of electrons using cathode-ray tubes.
• Determined the charge-to-mass ratio of an electron.
Cathode Ray with Field
R. S. Millikan• Performed experiments involving charged oil drops.
• Determined the magnitude of the charge on a single electron.
• Calculated the mass of the electron.
E. Rutherford• Atom has a dense center of positive charge called
the nucleus.
• Electrons travel around the nucleus at a relatively large distance.
Atomic / Nucleus Size
Chadwick
• Novel experiment to discover missing mass in the atom (nucleus)
• Why difficult to observe?
Periodic Table
Who ?How is it organized?
Know the group andseries names, metals,nonmetals, metalloids,solids, liquids, gases
Chpt 2 - Nomenclature
• Names <-> Chemical formulas• Binary and Polyatomic Ionic
• per -ate, -ate, -ite, hypo -ite• Roman numerals• ( ) if necessary in the formula
• Molecules (prefixes)• Acids
– Without oxygen– With oxygen
Nomenclature• Metal 1st -> ionic compound
– Binary - Metal retains its name nonmetal ends -ide– Know the normal charges to combine -make neutral– Use roman numerals for charge on transition
elements– Polyatomic ions memorize from Table 2.5 – Use ( ) for polyatomics, if more than 1 needed
• Nonmetal 1st -> molecule– Use prefixes!! Mono not used on 1st element– 1st element retains its name, other ends -ide
Nomenclature
• H 1st = Acids– No oxygen, also ends -ide
• hydro ____ ic acid
– Has oxygen, polyatomic ion (Table 2.5)• -ate becomes ____ic acid • -ite becomes ____ous acid
• H+1 used to balance polyatomic (-) charge
Common Polyatomic ions
Matter classification
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