Matter must
 Have mass
 Have volume (take up space)
Matter exists in three phases
 Solids (s)- fixed shape & volume
 Liquid (l)- fixed volume, takes the shape of the
container
 Gas (g)- takes both the volume and the shape of the
container
Matter is divided into 2 categories.
 Pure Substances
 Fixed composition
 Unique set of properties
 Mixtures
 Composed of two more substances physically mixed
Pure Substances
 Elements-type of matter than cannot be broken down
into two or more pure substances
 Elements can be divided into many categories
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Metals
Nonmetals
Metalloids
Families (Periodic Table)
 Compounds-more than one element
 Have new properties after chemically combined
Mixures
 Homogeneous-composition is the same throughout
 A solution is a liquid homogeneous mixture made of
solvents & solutes.
 Most solvents are liquids; however it can be a gas
 Heterogeneous- does not have a uniform composition
Separation Techiques
We are going to look at 3 types. There are more.
 Filtration
 Used for a heterogeneous solid-liquid mixture
 Distillation
 Homogeneous solid-liquid mixture
 Also liquid-liquid mixtures in which one liquid can be
evaporated
 Chromatography
 Liquid-liquid mixture
 Liquid-gas mixture
 Gas-gas mixture
Significant Figures
 Uncertainty of at least one unit in the last digit
 2.00 mL = 3 SF
 2.0 mL = 2 SF
 2 mL = 1 SF
 0.002 mL= 1 SF
Rules
 Zeros appearing between nonzero digits are significant
 Zeros appearing in front of all nonzero digits are NOT
significant.
 Zeros at the end of a number and to the right of a decimal
point are significant.
 A decimal point placed after zeros indicates that they are
significant.
 Trailing zeros without decimals are questionable
 75000 may be 2-5 SF
 7.5 x 104 = 2 SF
 7.50 x 104= 3 SF
 Assume not significant in the book therefore
75000= 2SF
Rules
 Multiplying & Dividing
 The # of SF in the result is the same as quantity of smallest
# of SF
 Adding & Subtracting
 The number of decimal places in the result is the same with
the smallest decimal
 Rounding
 If less than 5… leave last digit unchanged
 If greater than 5…add one to the last digit
 If equal to 5…round even

Round 14.575 to 2SF= 14
Rules
 Multiple Operations
 Carry out all steps with complete number of digits
 Go back to find the # of SF at each step
 Round at the end
 ALWAYS SHOW WORK AND USE YOUR UNITS!!!
How many Sig Figs?
1. 0.00800 in
2. 52.000 nm
3. 800 ns
4. 4.30 x 104 kg
5. 5060 g
Solve the problem with correct SF.
Box in your answer.
1. 2.505 x 0.0920 x 451.08=
2. 0.0810 + 7.168 + 1.50 =
3. 5.20/8.973=
***When putting in your calculator remember to use () to
make calculator do order of operations correctly.
Conversions
 When you make a conversion, choose the factor that
cancels out the initial unit.
 The actual conversion factor does not count on
significant figures
 Use the number of significant figures in the initial
measurement given
 Remember what % means mathematically. When
given a % use the unit shown in the problem.
 52% mL = 52 mL/ 100 mL
 0.07% L = 0.07 L/ 100
Examples
 3 hr to sec
 5.27 Mg to lb (Mg= mega grams)
 0.53 mi to m
 55.25 mi to km
 11.6 mL to in3
Properties of Substances
 Every pure substance has its own unique set of
properties
 Chemist use these properties for identification
 2 ways of grouping these properties
Intensive & Extensive Properties
 Intensive Properties (do not depend on amount)
***chemist use these to identify
 These are a few examples


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Density
Melting pt
Boiling pt
 Extensive Properties (depend on amount )
 Mass
 Volume
Physical & Chemical Properites
 Physical- do not change the substance
 Theses are just a few examples
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Density
Melting pt
Boiling pt
Solubility
Color
 Chemical-when a new substance is formed
 Reactivity
 Flammability
Density
 Denisty= mass/volume
 Mass= grams
 Volume= cm3, mL, L
 Be sure to show all work and units!!!!!
Examples

The density of Al is 2.70 g/mL. What is the volume
of 8.21 grams?

The density of Hg is 13.5 g/mL. How many grams
are in 5.0 mL?
Examples
 A sample of metal in a small weighing dish had a mass
of 59.61g. The dish had a mass of 0.58 g. When the
metal was added to the water, the water level rose 9
mL.
 What is the mass of the metal?
 What is the density of the metal?
Examples
 A sample of metal with a mass of 10.06g was placed in
a flask with a volume of 65.0 mL. To fill the flask, 35.7
g Hg (density= 13.5 g/mL) must be added to the metal.
What is the density of the metal?
Moles to grams to particles
 Atomic Mass= mass on the periodic table
 Avogadro’s Number
 Symbol NA
 6.022 x 1023
 It represents the number of atoms of an element in a
samples whose mass in grams is equal to the atomic
mass of that element
 6.022 x 1023 H atoms= 1.008 g H
 6.022 x 1023 N atoms = 14.001 g N
Examples
 Find the mass of a N atom
 Find the number of N atoms in 7.00 grams.
Moles and Molar Mass
 Moles
 1 mole = Avogadro’s Number
 1 mole = 6.022 x 1023
 Molar Mass
 Units are g/mol
 Same as formula mass
Examples
 13 g of caffeine, C4H5N2O
 Convert to moles
 Convert from moles to atoms
 Convert from atoms to Number of Carbon atoms