Matter and Matter and MeasurementMeasurement
Chapter 1Chapter 1
The Scientific MethodThe Scientific Method1.1. Observations – something that is Observations – something that is
witnessed and can be recordedwitnessed and can be recorded QualitativeQualitative QuantitativeQuantitative
2.2. HypothesisHypothesis3.3. ExperimentExperiment4.4. TheoryTheory
1. Tested hypotheses that explains WHY nature behaves in a certain way
2. Change as more info become available
Is the method used to determine the Is the method used to determine the Kentucky Derby winner a qualitative Kentucky Derby winner a qualitative measurement or a quantitative measurement or a quantitative measurement? Explain.measurement? Explain.
Classification of MatterClassification of MatterMatterMatter – anything that takes up – anything that takes up
space and has massspace and has mass
1.1. SolidsSolids
2.2. LiquidsLiquids
3.3. GasesGases
What can you tell me about the What can you tell me about the shape, volume, and shape, volume, and
compressabilty of the above?compressabilty of the above?
MixturesMixtures – matter of variable – matter of variable compositioncomposition
HomogeneousHomogeneous:: Uniform in composition; having Uniform in composition; having
visibly indistinguishable partsvisibly indistinguishable parts HeterogeneousHeterogeneous:: Not uniform in composition; Not uniform in composition;
visually distinguishable partsvisually distinguishable parts
Pure SubstancesPure Substances Elements:Elements:cannot be decomposed into cannot be decomposed into
simpler substancessimpler substances Compounds:Compounds:Two or more elements interacting Two or more elements interacting
with one anotherwith one another Law of Definite proportionsLaw of Definite proportions::The elemental composition of a The elemental composition of a
pure compound is always the pure compound is always the samesame
Properties of MatterProperties of MatterPhysical PropertiesPhysical Properties
1.1. Measured without changing the Measured without changing the identity and composition of identity and composition of substancesubstance
2.2. Includes color, odor, density, Includes color, odor, density, melting/boiling point, and hardnessmelting/boiling point, and hardness
Chemical PropertiesChemical Properties
1.1. Describes the way a substance may Describes the way a substance may change or change or reactreact to form other to form other substancessubstances
Intensive PropertiesIntensive Properties
1.1. Doesn’t depend on the amount Doesn’t depend on the amount in a samplein a sample
2.2. Used to identify substancesUsed to identify substances
3.3. Ex: temperature, melting point, Ex: temperature, melting point, density…density…
Extensive PropertiesExtensive Properties
1.1. Depends on the quantity of the Depends on the quantity of the samplesample
2.2. Ex: mass, volume …Ex: mass, volume …
Scientific NotationScientific Notation•Also known as exponential notationexponential notation
•Way to write very small and very large numbers using powers of ten.
•Answers in Sci. Notation should have ONLY 1 # (1-9) to the left of the decimal
3.6 x 104 = 36 000 5.8 x 10-3 = 0.0058
Why would that be useful?
MultiplicationMultiplication1)Multiply the Coefficients
2)Add the Exponents
(3.0 x 104) x (2.0 x 102) =
(3.0 x 2.0) x 104+2 = 6.0 x 106
DivisionDivision
1)Divide the coefficients
2)2)Subtract theSubtract the exponentsexponents.
3.0 x 104 = 3.0 x 104-2 = 1.5 x 102
2.0 x 102 2.0
Fixing the exponent:Fixing the exponent:
Move the decimal 1 space to the Move the decimal 1 space to the Left Left for every time you for every time you ADD ADD ONEONE to the exponent to the exponent
Move the decimal 1 to the Move the decimal 1 to the RightRight for every time you for every time you SUBTRACT SUBTRACT ONEONE from the exponent from the exponent
Addition and Addition and SubtractionSubtraction
1)Make the exponents the same. (pick highest exponent)
2) Add or Subtract the coefficients(5.40 x 103) + (6.0 x 102) =
(5.40 x 103) + (0.60 x 100.60 x 1033) = 6.00 x 103
Units of MeasurementUnits of Measurement
Measurements include two parts: Measurements include two parts: a a NumberNumber and and ScaleScale (units) … a (units) … a number without units is number without units is worthless!worthless!
The Fundamental SI UnitsThe Fundamental SI UnitsPhysical QuantityPhysical Quantity UnitUnit
AbbreviationAbbreviation
MassMass KilogramKilogram kgkg
LengthLength MeterMeter mm
TimeTime SecondSecond s (sec)s (sec)
TemperatureTemperature KelvinKelvin KK
Amount of substanceAmount of substance MoleMolemolmol
Electric currentElectric current AmpereAmpere AA
Luminous intensityLuminous intensity CandelaCandela cdcd
Standard SI prefixes for ChemistryStandard SI prefixes for ChemistryPrefixPrefix Unit Unit
AbbreviatioAbbreviationn
ExponentExponent(numerical value (numerical value
compared to base)compared to base)
MegaMega MM 1010-6-6
KiloKilo KK 1010-3-3
DeciDeci dd 101011
CentiCenti cc 101022
MilliMilli mm 101033
MicroMicro 101066
NanoNano nn 101099
PicoPico pp 10101212
TemperatureTemperature Celsius (Celsius (ooC) and Kelvin (K):C) and Kelvin (K):
1.1. K = K = ooC + 273C + 273
2.2. ooC = K – 273C = K – 273
3.3. The size of the temperature unit is The size of the temperature unit is the samethe same
FahrenheitFahrenheit
1.1. ooC = (5/9)(C = (5/9)(ooF – 32)F – 32)
2.2. ooF = (9/5)(F = (9/5)(ooC) + 32C) + 32
DensityDensity
The amount of mass in a unit of The amount of mass in a unit of volume of a substancevolume of a substance
Density = Mass / VolumeDensity = Mass / Volume
Uncertainty in MeasurementUncertainty in Measurement
A digit that must be A digit that must be estimatedestimated isis called called uncertainuncertain. A . A measurementmeasurement always has some always has some degree of uncertainty because…degree of uncertainty because…
1.1. it is performed with instrumentsit is performed with instruments2.2. no instrument can read an no instrument can read an
infinite number of decimal placesinfinite number of decimal places
is a measure of how close a measurement comes to the actual or true value.
is a measure of how close a series of measurements are to one another.
If all three darts were on the bullseye, you would be both accurateaccurate and preciseprecise.
ErrorsErrorsRandom Error (Indeterminate Error)Random Error (Indeterminate Error)
1.1. Measurement may be high or lowMeasurement may be high or low
2.2. Caused by interpretation of uncertain Caused by interpretation of uncertain digit or procedural ineptnessdigit or procedural ineptness
Systematic Error (Determinate Error)Systematic Error (Determinate Error)
1.1. Always occurs in the same directionAlways occurs in the same direction
2.2. Caused by poor technique or incorrect Caused by poor technique or incorrect calibration (gun sight set high/low; calibration (gun sight set high/low; balance improperly zeroed, balance improperly zeroed, thermometer improperly markedthermometer improperly marked
accepted value - experimental value
accepted valueaccepted value = the correct value
experimental valueexperimental value = the value measured in the lab
is the absolute value of the errorerror divided by the accepted valueaccepted value, multiplied by 100%.
% Error = error x 100%
accepted value
All of the digits that are known, plus a last digit that is estimated.
Sig. Figs. Matter all year, on all assignments, make sure to follow rules!
For AP test… good rule of thumb to use3 significant figures (graders give you a+/- 1 cushion)
1) Nonzero digits are always 1) Nonzero digits are always significant.significant.
ex: 1, 2, 3, 4…9ex: 1, 2, 3, 4…9
Rules to Determine if a digit is Rules to Determine if a digit is Significant:Significant:
Rules to Determine if a digit is Rules to Determine if a digit is Significant:Significant:
2) Zeros between nonzero 2) Zeros between nonzero digits are significantdigits are significant
Ex: 2005 , 107 , 250000023Ex: 2005 , 107 , 250000023
4 3 9
Rules to Determine if a digit is Rules to Determine if a digit is Significant:Significant:
3) Leftmost zeros appearing in 3) Leftmost zeros appearing in front of nonzero digits are front of nonzero digits are NOT SIGNIFICANTNOT SIGNIFICANT. They act . They act as placeholders.as placeholders.
Ex: 0.Ex: 0.00007, 7, 00.12 , 0..12 , 0.000000434434
1 2 3
Rules to Determine if a digit is Rules to Determine if a digit is Significant:Significant:
4) Zeros at the end of a 4) Zeros at the end of a number and to the right of a number and to the right of a decimal point are always decimal point are always significant.significant.
Ex: 34.00, 10.00, 0.400Ex: 34.00, 10.00, 0.4004 4 3
Rules to Determine if a digit is Rules to Determine if a digit is Significant:Significant:
5) Zeros at the end of a whole 5) Zeros at the end of a whole number are not significant.number are not significant.
Ex: 10, 100, 4500 … Ex: 10, 100, 4500 …
1 1 2
Pacific/Atlantic RulePacific/Atlantic Rule If a decimal is If a decimal is PresentPresent, start on , start on
the the PacificPacific side of the number side of the number and every number counts after and every number counts after the first non-zero digitthe first non-zero digit
If a decimal is If a decimal is AbsentAbsent, start on , start on the the AtlanticAtlantic side of the number side of the number and every number counts after and every number counts after the first non-zero digit.the first non-zero digit.
A) 5000 =
B) 0.0234 =
C) 10.0052 =
D) 25.000 =
1 sig. fig.
3 sig. figs.
6 sig. figs.
5 sig. figs.
Round the answer to the same number of significant figures as the measurement with the least number of significant figures.
7.55 x 0.34 = 2.567 = 2.6
CaluculationCaluculation Calculator SaysCalculator SaysAnswerAnswer3.24m x 7.0 m 22.68m2 10.2 m2
100.0g / 23.7g 4.21940 g/cm34.22 g/cm3
0.02cm x 2.371cm
710m / 3.0s
0.04742cm2
236.66667 m/s
0.05cm2
240 m/s
Round the answer to the same number of decimal places as the measurement with the least number of decimal places.
1.2 + 3.52 + 2.431 = 7.151 = 7.2
CaluculationCaluculation Calculator SaysCalculator SaysAnswerAnswer3.24m + 7.0 m 10.24 m 10.2 m
100.0g – 23.73g 76.27g 76.3g
0.02cm + 2.371cm
713.1L – 3.872L
2.391cm
709.228L
2.39cm
709.2L
Dimensional AnalysisDimensional Analysis
Unit Conversion Questions:Unit Conversion Questions: What unit am I given?What unit am I given? What units must be in my What units must be in my
answer?answer? What is (are) my conversion What is (are) my conversion
factor(s)?factor(s)?
Full credit will not be given on D.A. Full credit will not be given on D.A. problems in which you do not problems in which you do not
perform the following:perform the following:
1.1. Observe sig. fig. rulesObserve sig. fig. rules
2.2. Label all steps with correct unitsLabel all steps with correct units
3.3. Correctly label and ID answerCorrectly label and ID answer
4.4. Solve problem in manner that can Solve problem in manner that can be understood by the readerbe understood by the reader
Why important? Why am I being Why important? Why am I being a jerk about this?a jerk about this?