honors chemistry unit a: matter and...
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HONORS CHEMISTRYUnit A: Matter and Measurements
CHAPTER ONE: MATTER AND CHANGE
WHAT IS CHEMISTRY?uCHEMISTRY is the study of the composition,
structure, and properties of matter, the process that matter undergoes, and the energy changes that accompany these processes.
WHAT IS MATTER?uMATTER is anything that has mass and
volume – no matter how small the measurement.
uMASS is a measure of the amount of matter
uVOLUME is a measure of the space taken up by matter
WHAT IS AN ATOM?uATOMS are the smallest unit of an element
that maintains the chemical identity of that element
WHAT IS AN ELEMENT?uELEMENTS are pure substances that cannot
be broken down into simpler, stable substances and are made of only a single kind of atom.
WHAT IS A COMPOUND?uCOMPOUNDS are substances that can be
broken down into simple stable substances. Compounds are made from two or more elements that are chemically bonded
PROPERTIES OF MATTERuPROPERTIES of matter help to define and
classify substances. They can reveal the identify of an unknown substance.
uEXTENSIVE PROPERTIES depend on the amount of matter presentuEx. MASS, VOLUME, ENERGY
uINTENSIVE PROPERTIES do not depend on the amount of matter presentuEx. DENSITY, m.p., b.p., CONDUCTIVITY
PHYSICAL PROPERTIESuPHYSICAL PROPERTIES of matter can be
observed w/o changing the identity of the substance.
uPHYSICAL CHANGE doesn’t change the identity of the substanceuEx. Cutting, Grinding, Phase Changes
CHEMICAL PROPERTIESuCHEMICAL PROPERTIES of matter relate to a
substance’s ability to undergo change to form a new substance.
uCHEMICAL CHANGE results in a substance(s) being converted to a new substance(s)uEx. Combustion, Oxidation, Decomposition
CHEMICAL REACTIONuCHEMICAL REACTION is a process that involves
a chemical changeuReactants change to form new Products
CONSERVATION OF ENERGY & MATTER
uIn a chemical reaction matter is neither created nor destroyed. It can be accounted for and converted.
uIn a chemical reaction energy can be absorbed (endothermic) or released (exothermic), but not created or destroyed.
CLASSIFICATION OF MATTER
uMatter exists in a variety of forms and divided into two major types: Mixtures & Pure Substances
MIXTURESuMIXTURES are a blend of two or more kinds of
matter. Each substance retains its own properties.
MIXTURE GROUPSuHOMOGENEOUS MIXTURES are uniform and
appear as a single substance. Homogeneous mixtures are also called solutions
uHETEROGENEOUS MIXTURES are non-uniformuMixtures can often be physically separated by
filtration, vaporization, or other lab techniques.
PURE SUBSTANCESuPURE SUBSTANCES have a fixed composition for
all samples. They are either Elements or Compounds.
The Periodic Table of the Elements
uElements are organized on The Periodic TableuOver 100 elements are knownuElements are organized into Groups/Families
and Periods.uElements are also classified as Metals,
Nonmetals, and Metalloids.
Types of ElementsuMETALS are good conductors, malleable, and
are ductile and have luster. (Cu)uNONMETALS are poor conductors, brittle, and
usually gases at room temperature. (Ne)uMETALLOIDS are a small group of elements that
share characteristics with metals and nonmetals. (Si)
HONORS CHEMISTRYUnit A: Matter and MeasurementsCHAPTER TWO: MEASUREMENTS & CALCULATIONS
SI MeasurementuSI is the universal measurement system used
by scientistsuMEASUREMENTS represent quantities
(descriptive amounts)uQUANTITY is something that has magnitude,
size, or amount (numerical value)
SI BASESuThere are 7 SI bases and many derived or
combination unitsuThe “Big 5” are LENGTH, MASS, TIME,
TEMPERATURE, and AMOUNT OF SUBSTSANCE
MASSuSI Unit: Kilogram (kg)u1 kg = 1,000 g = 1,000,000 mguMASS is not the same as WEIGHTuWEIGHT is a force dependent upon gravity
LENGTHuSI Unit: Meter (m)u1 km = 1,000 m = 1,000,000 mm
AMOUNT (of a substance)uSI Unit: Mole (mol)u1 mole = 6.02 x 1023
uThe MOLE is a really large number that is useful when quantifying really small things like atoms
TEMPERATUREuSI Unit: Kelvin (K)uThe KELVIN scale has no negative values and
has incremental change equal to the CELCIUS scale
u△1◦C = △1Ku0 K = -273 ◦CuK à ◦C (subtract 273)u◦C à K (add 273)
VOLUMEuSI Unit: Meter (m3)uVOLUME is a derived unit – length in 3DuVOLUME units are often expressed as:
uLiters (L), Mililiters (mL), Cubic Centimeters (cm3)u1 L = 1,000 mL = 1,000 cm3
DENSITYuDENSITY is the ratio of mass per unit volumeuDENSITY = D = M/VuDENSITY units are often expressed as:
uKilograms per cubic meter (kg/m3)uGrams per cubic milliliter (g/mL)
CONVERSION FACTORSuA ratio derived from an equality between two
different unitsuUsed to convert one unit to anotheruFormatted as FRACTIONS
uDesired “New” unit on TOPuStarting “Old” unit on BOTTOM
DIMENSIONAL ANALYSISuMath technique that uses conversion factors to
solve problems with units of measureuMultiplication & Fractions!
uExamples on the board: uTime, Mass, Moles
ACCURACY & PRECISIONuACCURACY refers to the closeness of a
measurement to the correct or accepted valueuPRECISION refers to the closeness of a set of
measurements of the same quantity
PERCENT ERRORu% ERROR compares the accuracy of an
experimental value with an accepted valueuKind of like “grade” for your experimental
measurements or data uValues closer to 0% are best
Measurement ErroruNo measurements are “perfect”uErrors in measurement are due to human and
instrumental limitationsuEstimation is involved in the final questionable digit of
a measurementuExamples: 2.5 days vs. 2 days, 12 hours, 1.5 minutesuSun vs. Clock
Sig FigsuSIGNIFICANT FIGURES in a measurement consist of all
the digits known with certainty plus one final digit, which is estimated or uncertain
Sig Fig OperationsuADDITION & SUBTRACTION: the answer must have the
same number of digits to the right of the decimal point as there are in the measurement with the fewest digits to the right of the decimal point
Sig Fig OperationsuMULTIPLICATION & DIVISION: the answer can only
have as many significant figures as the measurement with the fewest sig figs
Scientific NotationuSCIENTIFIC NOTATION expresses quantities with non-
significant zeros in a compact formuM x 10n (Avogadro’s # 6.02x1023)u The “M” value must be greater than or equal to 1
and less than 10
Scientific Notation Rules
ProportionalityuDIRECTLY PROPORTIONAL: the quotient of the two
variables is constant (y/x = constant)uTemperature & Volume
u INVERSELY PROPORTIONAL: the product of the two variables is constant (xy = constant)uPressure & Volume
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