Matter & Measurement Notes
A. What is chemistry?
1. Matter – anything that has mass and volume
2. Chemistry – The study of all matter and the changes it can undergoes.
i. Chemistry is called a central science because it overlaps so many other sciences.
3. Chemical – matter that has a defined composition.
i. When a chemicals composition change it is called chemical reaction
ii. Chemical reaction - The process in which one or more substances change to produce one or
more new substances.
B. What is Matter?
1. Another way to think about matter is by just thinking about any thing, what your thinking about now is
an example of matter
2. Because matter can be anything, chemists have come up with ways to describe it more specifically
i. One of the most common ways to describe matter is by describing what state it is in
ii. States of matter – the physical form matter is in, solid, liquid and gas
State
Shape
Volume
Solid
Fixed
Fixed
Liquid
Not Fixed
Fixed
Gas
Not Fixed
Not fixed
Structure
(Bonds between the
particles)
Rigid structure
(lots of strong bonds
between particles)
Non-ridged structure
(some bonds between
particles)
No structure
(Very weak or no
bonds between
particles)
Movement of the
particles that make it up
Very slight vibration
Some movement but not
much
Lots of movement
between particles
A. What are some Chemical properties of matter?
a. Chemical Property – a characteristic of matter that describes how that substance reacts with other
substances
i. Chemical properties of matter cant be observed without chemically changing a substance
ii. Examples of physical properties are: reactivity with oxygen, reactivity to light, ability to emit
radiation
B. What are some physical properties of matter?
a. Physical property – a characteristic of a substance that can be observed without chemically changing it
b. Examples of physical characteristics are mass, volume, weight and density
i. Mass – the measure of the amount of matter within an object
1. Chemists measure mass using a scale
ii. Volume - the amount of space matter takes up
1. Volume is measured using a graduated cylinder
iii. Density- is defined as mass per unit volume
1. It is usually expressed as g/ml.
2. Low density materials feel Light for their size , while high density materials feel heavy.
3. Materials with a lower density will float above materials with a higher density.
4. Since most materials have a unique density, the density of a material can be used to
help identify it
Density = mass or d = m
volume
v
A. What is matter made out of?
a. All matter is made composed of one or a combination of atoms
b. Atoms – the smallest peace of matter you can get which still has all the same chemical and physical
properties
c. There are about 110 different types of atoms that have been found or created in the universe
d. All atoms come from stars
e. The periodic table is an organized list of all the atoms known to man
f. Atoms bind together to make molecules
B. What are some examples of Pure matter?
a. Pure substances – a sample of matter that is composed of only one type of particle (atom or molecule)
i. A pure substance can be made of only one type of atom like gold (Au), aluminum (Al), or helium
(H) or 1 type of molecule like carbon dioxide (CO2), water (H2O), or caffeine (C8H10N4O2)
ii. Two main types of pure substances are Elements and Compounds
C. What are Elements?
a. Elements – a pure form of matter that consists of only one atom
i. Elements can not be separated into simpler substances
ii. Chemists represent elements using chemical symbols, which have 1 or two letters
Element name
Chemical Symbol
Carbon
C
Hydrogen
H
Nitrogen
N
Lead
Pb
Gold
Au
Uranium
U
Tungsten
W
D. What are compounds?
a. Compounds – a pure form of matter that consists of more than one atom bound together in a fixed ratio
(CO2 = 1 C and 2 Os)
i. Compounds can be separated into similar substances (elements) but only by chemically
changing the compounds
1. Ex: CO2 is the gas you breath out (compound), it can be separated into carbon (Black
stuff in your pencil) and oxygen (rocket fuel), but neither of those similar substances
have the same chemical and physical properties
ii. Compounds are represented by chemical formulas
1. Examples of chemical formulas H2, CO2, H2O, C8H10N4O2
iii. Compounds are considered to be “pure” because you can isolate the compounds so that only 1
compound exists in a given place
1. For instance you can remove the caffeine from coffee and be left with only powdered
caffeine in a jar
Which of these is an element? Which of these is a compound? Which of these is a pure substance?
E. What are mixtures?
a. Mixture – A mixture is a blend of two or more kinds of matter, each of which retains its own identity and
properties
b. There are two types of mixtures
i. Homogeneous Mixture – A homogeneous mixture is one that is uniform in appearance
ii. Heterogeneous Mixtures – The substances making up the mixture are not evenly mixed through
out
Which of the above is a homogeneous mixture? Which is a heterogeneous mixture?
1. How do we measure matter?
a. The Metric system - is the measurement system used by all scientists.
i. It is based on The Powers of 10 (10x)
ii. can be used to measure:
1. Length
a. Meter (m) basic unit of length , measured with a meter stick
2. Mass,
a. Kilogram (kg) basic unit of mass , measured with a scale
3. Amount of space a substance takes up
a. Leter (l) basic unit of volume, measured with a graduated cylinder
meter
liter
gram
A. Is there an easer way to express such large or small numbers?
c. A way to express very large or small numbers without all the stupid 0’s is by using scientific notation
d. Scientific notation condenses large or small numbers by numerically stating what power of ten you must
multiply a number by in order to get the true number
i. Ex: 365,000,000,000g  3.65 x 1011g or 0.00000052kg  5.2 x10-7kg
e. There are 3 things to remember when using scientific notation:
i. Never use more than 1 number before the decimal point
ii. Positive exponents of ten move the decimal point to the right
iii. Negative exponents of ten move the decimal point to the left
B. How do you work with Scientific notation?
f. In your calculator you must use the scientific notation key and parenthesis
i. Scientific notation key:
1. May be a “second” function
2. Could be E, Or EE, or x10 button
3. It isn’t the e button
4. Always use parenthesis
C.
What is the easiest way to work with these numbers and units?
g. Dimensional analysis is the mathematical process that scientists use to convert into and out of units
h. Dimensional analysis works by setting up a series of fractions which all equal 1 and than multiplying all
those fractions together
i. You never change the number because you are always multiplying it by 1, you only change the units
that number is in
i. Ex: How Km is 56 feet? (1 m = 3.2ft & 1 km = 1000m)
 56 ft   1m   1km   56 ft 

 x
 x
  
 x1x1 


 1   3.2 ft   1000m   1 
j.
Steps for performing dimensional analysis:
i. Start with what you are given on top of the first fraction
ii. Cancel out unit by putting it on bottom of the next fraction
iii. To solve multiply what is on top, multiply what is on bottom and divide
1. What is a mole?
a. Mole (Molecular unit) – 6.02x1023 atoms or molecules (602,000,000,000,000,000,000,000 or 602
sextillion)
b. The number “1 mole” is based on the number of atoms in exactly 12.0000g of Carbon – 12.
c. Avogadro’s constant - The number a mole, 6.02x1023
Section 1-4: Measurements & Accuracy
1) Accuracy is how close a measurement is to the true value.
i) Significant digits is what chemists use to determine the accuracy of a number
ii) The Atlantic-Pacific rule is how you determine the number of significant digits a number has
b) Atlantic pacific rule:
i) If a decimal point is Present, ignore zeros on the Pacific (left) side.
ii) If the decimal point is Absent, ignore zeros on the Atlantic (right) side.
iii) Everything else is significant
c) The more significant digits a number has the more accurate it is
d) How do you do arithmetic with significant figures?
i) Your answer can only be as accurate as the least accurate measurement.
ii) Never include more sig figs in the answer than the least amount of sig figs in the question
Number
Atlantic – Pacific Rule
Number of Significant Figures
0.001010
Decimal point Present:
Ignore zeros on the Pacific side.
4 sig. digits.
0.001010
0.30000
Decimal point Present:
Ignore zeros on the Pacific side.
5 sig. digits.
0.30000
100.0000
Decimal point Present:
Ignore zeros on the Pacific side
(none!)
7 sig. digits.
100.0000
12303000
Decimal point Absent:
Ignore zeros on the Atlantic side.
5 sig. digits.
12303000
12303000.0
Decimal point Present:
Ignore zeros on the Pacific side
none.
9 sig. digits
12303000.0
23000
Decimal point Absent:
Ignore zeros on the Atlantic side.
2 sig. digits
23000