Unit 1 - Matter-Properties and Changes (Ch. 3)
Safety
Scientific method
MSDS
Properties of Matter
I.
Physical Properties
A. Definition: characteristics that can be measured or observed without changing the
sample’s composition.
B. Examples:
1. Color
10. hardness
2. odor
11. conductivity
3. melting point
12. malleability
4. density
13. ductility
5. taste
14. temperature
6. boiling point
15. volume
7. phase
16. mass
8. texture
17. length
9. shape
18. Solubility
Etc.
C. Two types of Physical Properties:
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1. Extensive properties
a. Definition: physical property that depends on the amount of matter present.
Basically anything that can be measured.
b. Examples:
Mass, Length, Volume
2. Intensive properties
a. Definition: physical property that does not depend on the amount of matter
present.
b. Examples:
Density, color, melting point, boiling point
II.
Chemical Properties
A. Definition: the ability of a substance to combine with or change into one or more
other substances.
B. Examples:
1. reactivity
2. pH
3. flammability
4. toxicity
5. corrosiveness
6. chemical stability
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III.
States of Matter
Solid
has definite shape and definite volume
On the periodic table, solids at room temperature are denoted by black
Liquid flows, has definite volume but no definite shape
On the periodic table, liquids at room temperature are denoted by blue
Gas - has no definite shape and no definite volume
The term gas refers to a substance that is naturally in the gaseous state at room
temperature. On the periodic table, gases are denoted by red. The term vapor
refers to the gaseous state of a substance that is a solid or gas at room
temperature.
Ex.
Steam is a vapor because water exists as a liquid at room
temperature.
Plasma the fourth state of matter and is the most abundant in the universe, but not here
on earth. Stars are made up of plasma.
Changes in Matter
I.
Physical Changes
A. Definition: a change in which the same substance is present before and after the
change.(its composition does not change)
B. Examples:
Cutting a sheet of paper, sawing a piece of wood in half, tearing lettuce, crushing ice,
dissolving, all phase changes
II.
Chemical Changes
A. Definition: a change of conditions that creates new substances with new properties
B. Examples:
Iron + Oxygen → rust (Iron(III) oxide)
Sodium + Chlorine → table salt (NaCl)
Burning a match, digesting food, silver tarnishing, iron rusting, corrosion,
combustion, oxidation
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C. Recognizing a chemical change (rules of thumb):
1. formation of a solid which is called a _precipitate_______________.
2. change in color
3. effervescence (production of a gas)
4. change in temperature
5. change in odor
6. production of light/heat
III.
Conservation of Mass
A. Law of Conservation of Mass - mass is neither created nor destroyed during a
chemical reaction. In equation form:
Mass reactants = Mass products
Practice Problem
In an experiment, 10.00 g of red mercury (II) oxide powder is placed in an open flask and
heated until it is converted to liquid mercury and oxygen gas. The liquid mercury has a
mass of 9.26g. What is the mass of oxygen formed in the reaction?
2HgO
→
Reactant
10.00 g =
2Hg + O2
Products
9.26 g + X
X = 10.00 g - 9.26 g = .74 g
Mixtures of Matter
I.
Matter
A. Definition – anything thing that takes up space and has mass.
B. Matter can be broken down into two categories: mixtures and pure substances.
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II.
Mixture
A. Definition: combination of two or more pure substances in which each pure
substance retains its individual chemical properties.
B. Examples: Sand and water; salt water
C. Types of Mixtures:
1. Heterogeneous Mixture
a. Definition: one that does not blend smoothly throughout and in which the
individual substances remain distinct; it has two or more distinct areas.
b. Examples:
Sand and water, granite, raising bread, salad dressing,
Orange juice (with pulp)
2. Homogeneous Mixture
a. Definition: has constant (uniform) composition throughout; it always has a
single phase.
b. Also called a solution
c. Examples:
Pure air, soda(Coca Cola), vinegar, salt water, alloy
III.
Separating Mixtures
Mixtures can be separated based on their physical properties and the techniques used can
be easy or difficult.
For instance:
How would you separate pennies and nickels?
Sorting
How would you separate sand and iron filings?
Magnet
How would you separate salt and water?
Evaporation, boiling
Numerous techniques have been developed to separate mixtures besides the ones named
above.
Techniques
1. Sorting - by color, shape, texture, etc.
2. Magnet – separates magnetic from nonmagnetic material.
3. Density - “sink vs. float” ( Water has a density of 1 g/mL. Oil floats on water
because oil's density is less than 1 g/mL)
4. Filtration - use of a porous barrier to separate solid from liquid
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(ex. sand from salt water)
5. Distillation - Based on differences in boiling points.
(2 liquids can be separated by evaporation/condensation)
6. Crystallization - Results in the formation of solid crystals from solution.
7. Chromatography - separates components of a mixtures based on the tendency of
each to travel or be drawn across the surface of another material.
8. Vaporization – separates a solution. (ex. Salt from water)
IV.
Pure Substances
Pure Substances
A. Definition: Matter that has uniform and unchanging composition.
B. Types of Pure Substances:
1. Element
a. Definition: a pure substance that cannot be separated into simpler substances
by physical or chemical means.
1) monatomic – unbonded atoms ex/ Fe, Al, Cu, He
2) diatomic – atoms not found free in nature unless bonded to an identical
atom. Ex/ Br2, I2, N2, Cl2, H2, O2, F2
b. Displayed on the Periodic table.
Has 18 groups – vertical columns
Has 7 periods - horizontal rows
2. Compound
a. Definition: combination of two or more different elements that are combined
chemically.
b. Examples: NaCl, SrBr2
Intro to Periodic Table
I.
Groups

Each vertical column is called a group or family
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

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II.
18 groups, numbered 1 to 18
Groups 1,2 and 13-18 are called main-group, or representative elements. They
are also labeled IA, IIA and IIIA-VIIIA respectively.
Groups 3-12 are called transition metals
Metals, Nonmetals and Metalloids



A stairstep line on the periodic table separates metals from nonmetals
Metals are to the left of the stairstep line
Nonmetals are to the right of the stairstep line
Properties of Metals
1. good conductors of heat and electricity
2. shiny
3. have high melting points
4. ductile
5. malleable
6. tend to lose electrons
Properties of Nonmetals
1. poor conductors of heat and electricity
2. dull
3. have low melting point
4. solids are brittle
5. tend to gain electrons
Properties of Metalloids
 All elements on either side of the stairstep line EXCEPT Aluminum
 They have properties of both metals and nonmetals
1. white or gray in color
2. conduct heat and electricity but not as well as metals
3. ductile
4. malleable
5. not as shiny as metals
6. solids
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