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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