Download Chemistry: Matter and Change

Matter—Properties and Change
Section 3.1 Properties of Matter
Section 3.2 Changes in Matter
Section 3.3 Mixtures of Matter
Section 3.4 Elements and
Compounds
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Section 3.1 Properties of Matter
• Identify the characteristics of a substance.
• Distinguish between physical and chemical
properties.
• Differentiate among the physical states of matter.
density: a ratio that compares the mass of an
object to its volume
Section 3.1 Properties of Matter (cont.)
states of matter
physical property
solid
extensive property
liquid
intensive property
gas
chemical property
vapor
Most common substances exist as
solids, liquids, and gases, which have
diverse physical and chemical
properties.
Substances
• Matter is anything that has mass and takes
up space.
• Matter is everything around us.
• Matter with a uniform and unchanging
composition is a substance.
States of Matter
• The physical forms of matter, either solid,
liquid, or gas, are called the states of
matter.
• Solids are a form of matter that
have their own definite shape and
volume.
• Liquids are a form of matter that
have a definite volume but take the
shape of the container.
States of Matter (cont.)
• Gases have no definite shape or
volume. They expand to fill their
container.
• Vapor refers to the gaseous state
of a substance that is a solid or
liquid at room temperature.
Physical Properties of Matter
• A physical property is a characteristic that
can be observed or measured without
changing the sample’s composition.
Physical Properties of Matter (cont.)
• Extensive properties are dependent on
the amount of substance present, such as
mass, length, or volume.
• Intensive properties are independent of the
amount of substance present, such as
density.
Chemical Properties of Matter
• The ability of a substance to combine with
or change into one or more other
substances is called a chemical property.
– Iron forming rust
– Copper turning green in the air
Observing Properties of Matter
• A substance can change form–an
important concept in chemistry.
• Chemical properties can change with specific
environmental conditions, such as
temperature and pressure.
Section 3.1 Assessment
Density is what kind of property?
A. atomic
B. intensive
C. extensive
D
C
A
0%
B
D. dependent
A. A
B. B
C. C
0%
0%
0%
D. D
Section 3.1 Assessment
What defines a gas?
A. Gases have a definite volume
and shape.
0%
A
D. Gases have a definite shape
but no definite volume.
0%
B
C. Gases have no definite volume or
shape.
A
B
C
D
0%
0%
D
A.
B.
C.
D.
C
B. Gases have a definite volume
but take the shape of their container.
Section 3.2 Changes in Matter
• Define physical change and list several common
physical changes.
• Define chemical change and list several indications
that a chemical change has taken place.
• Apply the law of conservation of mass to chemical
reactions.
observation: orderly, direct information gathering
about a phenomenon
Section 3.2 Changes in Matter (cont.)
physical change
phase change
chemical change
law of conservation of mass
Matter can undergo physical and
chemical changes.
Physical Changes
• A change that alters a substance without
changing its composition is known as a
physical change.
• A phase change is a transition of matter from
one state to another.
• Boiling, freezing, melting, and condensing all
describe phase changes in chemistry.
Chemical Changes
• A change that involves one or more
substances turning into new substances is
called a chemical change.
• Decomposing, rusting, exploding, burning, or
oxidizing are all terms that describe chemical
changes.
Conservation of Mass
• The law of conservation of mass states
that mass is neither created nor destroyed
in a chemical reaction, it is conserved.
• The mass of the reactants equals the mass of
the products.
massreactants = massproducts
Section 3.2 Assessment
When one substances turns into another,
what kind of change has taken place?
A. chemical reaction
B. physical reaction
D
A
0%
C
D. nuclear reaction
A. A
B. B
C. C
0%
0%
0%
D. D
B
C. extensive reaction
Section 3.2 Assessment
The law of conservation of mass states
that:
A. Matter can be created and destroyed.
B. Matter can be created but not destroyed.
0%
0%
D
0%
A
B
C
D
C
0%
A
D. The products of a reaction must
have the same mass as the
reactants.
A.
B.
C.
D.
B
C. The products of a reaction always
have a greater mass than the
reactants.
Section 3.3 Mixtures of Matter
• Contrast mixtures and substances.
• Classify mixtures as homogeneous or
heterogeneous.
• List and describe several techniques used to
separate mixtures.
substance: a form of matter that has a uniform and
unchanging composition; also known as a pure
substance
Section 3.3 Mixtures of Matter (cont.)
mixture
distillation
heterogeneous mixture
crystallization
homogeneous mixture
sublimation
solution
chromatography
filtration
Most everyday matter occurs as
mixtures—combinations of two or more
substances.
Mixtures
• A mixture is a combination of two or more
pure substances in which each pure
substance retains its individual chemical
properties.
• A homogenous mixture is a mixture where
the composition is constant throughout.
Mixtures (cont.)
• Homogeneous mixtures are also called
solutions.
• A heterogeneous mixture is a mixture where
the individual substances remain distinct.
Mixtures (cont.)
Separating Mixtures
• Filtration is a technique that uses a porous
barrier to separate a solid from a liquid in a
heterogeneous mixture.
• Distillation is a separation technique for
homogeneous mixtures that is based on the
differences in boiling points of substances.
• Crystallization is a separation technique for
homogenous mixtures that results in the
formation of pure solid particles from a
solution containing the dissolved substance.
Separating Mixtures (cont.)
• Sublimation is the process of a solid
changing directly to a gas, which can be
used to separate mixtures of solids when
one sublimates and the other does not.
• Chromatography is a technique that
separates the components of a mixture on
the basis of tendency of each to travel across
the surface of another material.
Section 3.3 Assessment
Which is NOT a technique for separating a
homogenous mixture?
A. crystallization
B. distillation
D
A
0%
C
D. chromatography
A. A
B. B
C. C
0%
0%
0%
D. D
B
C. filtration
Section 3.3 Assessment
Which of the following is a heterogeneous
mixture?
A. seawater
B. silver mercury amalgam
D
A
0%
C
D. salad dressing
A. A
B. B
C. C
0%
0%
0%
D. D
B
C. atmosphere
Section 3.4 Elements and Compounds
• Distinguish between elements and compounds.
• Describe the organization of elements in the periodic
table.
• Explain how all compounds obey the laws of definite
and multiple proportions.
proportion: the relation of one part to another or
to the whole with respect to quantity
Section 3.4 Elements and Compounds
(cont.)
element
law of definite proportions
periodic table
percent by mass
compound
law of multiple proportions
A compound is a combination of two or
more elements.
Elements
• An element is a pure substance that cannot
be separated into simpler substances by
physical or chemical means.
• 92 elements occur naturally on Earth.
• Each element has a unique name and a one,
two, or three-letter symbol.
• The periodic table organizes the elements
into a grid of horizontal rows called periods
and vertical columns called groups.
Compounds
• A compound is a made up of two or more
elements combined chemically.
• Most of the matter in the universe exists as
compounds.
• Table salt, NaCl, and water, H2O, are
compounds.
Compounds
(cont.)
• Elements can never be separated.
• Compounds can be broken into components
by chemical means.
Compounds
(cont.)
• This figure shows
electrolysis of
water to form
hydrogen and
oxygen.
Compounds
(cont.)
• The properties of a compound are different
from its component elements.
Law of Definite Proportions
• The law of definite proportions states
that a compound is always composed of
the same elements in the same proportion
by mass, no matter how large or small the
sample.
Law of Definite Proportions
(cont.)
• The relative amounts are expressed as
percent by mass, the ratio of the mass of
each element to the total mass of the
compound expressed as a percentage.
Law of Definite Proportions
(cont.)
• This table demonstrates that the percentages
of elements in sucrose remain the same
despite differences in sample amount.
Law of Multiple Proportions
• The law of multiple proportions states
that when different compounds are formed
by a combination of the same elements,
different masses of one element combine
with the same relative mass of the other
element in whole number ratios.
– H2O2 and H2O
– Copper(I) chloride and copper(II) chloride
Law of Multiple Proportions (cont.)
Section 3.4 Assessment
What is a period on the periodic table of
the elements?
A. a vertical columns
B. even numbered elements only
D
A
0%
C
D. the last vertical column only
A. A
B. B
C. C
0%
0%
0%
D. D
B
C. horizontal rows
Section 3.4 Assessment
An element is a substance that cannot be
A. divided into simpler substances.
B. combined to form a mixture.
C. combined to form an element.
D
C
A
0%
B
D. different phases.
A. A
B. B
C. C
0%
0%
0%
D. D
Section 3.1 Properties of Matter
Key Concepts
• The three common states of matter are solid, liquid,
and gas.
• Physical properties can be observed without altering a
substance’s composition.
• Chemical properties describe a substance’s ability to
combine with or change into one or more new
substances.
• External conditions can affect both physical and
chemical properties.
Section 3.2 Changes in Matter
Key Concepts
• A physical change alters the physical properties of a
substance without changing its composition.
• A chemical change, also known as a chemical reaction,
involves a change in a substance’s composition.
• In a chemical reaction, reactants form products.
• The law of conservation of mass states that mass is
neither created nor destroyed during a chemical
reaction; it is conserved.
massreactants = massproducts
Section 3.3 Mixtures of Matter
Key Concepts
• A mixture is a physical blend of two or more pure
substances in any proportion.
• Solutions are homogeneous mixtures.
• Mixtures can be separated by physical means.
Common separation techniques include filtration,
distillation, crystallization, sublimation, and
chromatography.
Section 3.4 Elements and Compounds
Key Concepts
• Elements cannot be broken down into simpler
substances.
• Elements are organized in the periodic table of the
elements.
• Compounds are chemical combinations of two or more
elements and their properties differ from the properties
of their component elements.
Section 3.4 Elements and Compounds
Key Concepts
(cont.)
• The law of definite proportions states that a
compound is always composed of the same
elements in the same proportions.
• The law of multiple proportions states that if elements
form more than one compound, those compounds will
have compositions that are whole-number multiples of
each other.
Which of the following is NOT a physical
property of water?
A. Ice melts at 0°C.
B. Water boils at 100.
D
A
0%
C
D. Water is a liquid at room
temperature.
A. A
B. B
C. C
0%
0%
0%
D. D
B
C. Water reacts violently with
pure sodium.
28.0 grams of nitrogen gas reacts
completely with 6.0 grams of hydrogen to
form 34.0 grams of ammonia. What does
this demonstrate?
A. the law of conservation of energy
A
0%
0%
A
B
C
D
0%
0%
D
D. the law of conservation of mass
C
C. distillation
A.
B.
C.
D.
B
B. sublimation
What is the best way to separate salt
dissolved in water?
A. sublimation
B. crystallization
D
A
0%
C
D. filtration
A. A
B. B
C. C
0%
0%
0%
D. D
B
C. freezing
Two or more elements chemically joined
form what?
A. substance
B. heterogeneous mixture
D
A
0%
C
D. compound
A. A
B. B
C. C
0%
0%
0%
D. D
B
C. homogenous solution
What is the ratio of oxygen to carbon in
carbon dioxide (CO2)?
A. 2:1
B. 1:2
D
A
0%
C
D. 1:3
A. A
B. B
C. C
0%
0%
0%
D. D
B
C. 1:1
Which is NOT a chemical reaction?
A. a car rusting
B. dissolving sugar in water
C. wood burning
D
C
A
0%
B
D. a banana ripening
A. A
B. B
C. C
0%
0%
0%
D. D
Which describes a substance that is in the
liquid state?
A. It has a definite shape.
B. It has no definite volume.
D
A
0%
C
D. It has a definite volume.
A. A
B. B
C. C
0%
0%
0%
D. D
B
C. It can be compressed into a
smaller volume.
Elements in the same period are likely to
have similar ____.
A. physical properties
B. densities
D
A
0%
C
D. melting points
A. A
B. B
C. C
0%
0%
0%
D. D
B
C. chemical properties
Filtration is an easy way to separate
what?
A. heterogeneous mixture
B. homogeneous mixture
D
A
0%
C
D. solutions
A. A
B. B
C. C
0%
0%
0%
D. D
B
C. compounds
Compounds can be broken into their
component elements by which of the
following?
A. crystallization
A
0%
D
D. chemical reaction
C
C. filtration
A. A
B. B
C. C
0%
0%
0%
D. D
B
B. distillation
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