Download Chemistry Test #1 Study Guide © Chris Khan

Chris Khan 2006
 Substance—a form of matter that has a definite composition and distinct properties
 Mixture—a combination of 2+ substances in which they retain their distinct ID’s
 Homogeneous mixture—where composition of mixture is same throughout
 Heterogeneous mixture—where composition is not uniform
 Element—cannot be separated physically
 Compound—substance of 2+ elements chemically united in fixed proportion
 Physical Property—can be observed without changing ID of substance
 Chemical Property—must make chemical change to observe
 Extensive Property—depends on amount of matter being considered
 Intensive Property—does not depend on amount of matter
 Mass—quantity of matter; Volume—length cubed; Density—mass/volume
 Macroscopic Properties—can be determined directly
 Microscopic Properties—must be determined by indirect method
 SI Units—internationally used: meter, kilogram, second, ampere, Kelvin, mole, joule, and cubic meter
 SI Prefixes—tera, giga, mega, kilo, deci, centi, milli, micro, nano pico
 Significant Figures—meaningful digits in a calculated quantity, based on the least amount of sig figs used in the calculation
 Dimensional Analysis—to solve for another unit by conversion; multiply given amount by conversion factor [i.e. 240 pennies * 1
dollar/100 pennies]
 John Dalton proposed the atomic theory that states three things:
o Law of Definite Proportions—different samples of same element contain came constituent elements in same proportion
by mass
o Law of Multiple Proportions—if two elements combine to form a compound, the masses of one element that combine
with a fixed mass of the other element are in ratios of small while numbers
o Law of Conservation of Mass—matter CANNOT be created or destroyed
o THE ATOM is the basic unit of an element
 JJ Thomson, in 1897, discovered electrons using the cathode ray tube;
when two metal plates are connected to a high voltage source, the
negatively charged plate [cathode] emits an invisible ray—the cathode
ray is drawn to the positively charged plate [anode] where it passes
through a hole and continues traveling to the other end of the tube—
when the ray strikes the specially coated surface, it makes light—When
the magnetic field is turned on only, the cathode ray strikes A [top],
when the electric field is turned on only, the ray strikes C [bottom] and
when both are on, it strikes B [middle].
 Marie Curie described radioactivity to describe the emission of
particles/radiation
 Alpha rays consist of positively charged particles; Beta—negative;
Gamma—none
 Ernest Rutherford, in 1910, performed the gold foil experiment, an
experiment that shot particles at a piece of gold foil—most pieces went
through the foil or slightly deflected, but every now and then, an alpha
particle actually bounced back (!)—this was a very surprising finding;
Rutherford was then able to propose that there must be a nucleus, or a
dense central core in the atom—the positively charged particles in the
nucleus are protons
 James Chadwick thought that there must be another subatomic particle in
the nucleus because it didn’t make sense to not have more stuff there, so he bombarded a sheet of Be with alpha particles and saw
high-energy radiation emitted; later experiments showed that other subatomic particles, called neutrons, had to exist; they have a
greater mass than protons
 Atomic Number [Z]—number of protons in the nucleus of each atom in an element
 Mass Number [A]—total number of neutrons and protons present in the nucleus of an atom of an element; mass number =
protons + neutrons
 Isotopes—atoms that have the same atomic number but different atomic masses
 In the Periodic Table, elements having similar chemical and physical properties are grouped—horizontal rows are periods and
vertical columns are groups
 Metals conduct stuff and Nonmetals don’t; Metalloids are similar to both
 Molecule—two atoms held together by chemical forces
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Diatomic Molecule—contains two atoms; Polyatomic Molecule—more than 2 atoms
Ion—atom with + or – charge; Cation—net positive charge; Anion—net negative charge
Allotrope—one of two or more distinct forms of an element
Organic Compounds have carbon while Inorganic don’t
Ionic Compounds—have a metal and a nonmetal
Molecular Compounds—have two of the same, not both metal and nonmetal
Naming Ionic Compounds—forget the number of each element, just name the Cation [first element which is metal—usually]
and then use the Polyatomic name chart to tell you what the anion [second part, not a metal] is
o For 1A, a +1 charge; 2A, +2; 5A, -3; 6A, -2; 7A, -1—for anything in the B’s, there’s no charge, but you must use a
Roman Numeral after the Cation before the anion
Naming Molecular Compounds—use prefixes to name the compound; name the first element and add –ide to the end of the
second element
Naming OXOAcids—if you add an O atom to the –ic acid, just make it per-…-ic acid; if you remove an O atom from the –ic
acid, just make it –ous acid; if you remove two O atoms from the –ic acid, just make it hypo-…-ous acid
Naming OXOAnions—if you remove the H ions from the –ic acid, just make it –ate; if you remove all the H ions from the –ous
acid, just make it –ite; if you remove H ions, but not all of them, indicate the number present
Hydrates have a specific number of water molecules attached to them; use the Greek prefixes before the H 2O