Matter and Change
Chapter 2
Objectives: You WILL be able to…
1.
ID properties of matter
2.
Define physical property and list several
3.
Differentiate 3 states of matter
4.
Describe physical change
5.
Categorize a sample of matter as a substance or a mixture
6.
Distinguish between homogeneous and heterogonous samples of matter
7.
Describe two ways that components of mixtures can be separated
8.
Explain the difference between element and compound
9.
Distinguish between a substance and a mixture
10.
ID the chemical symbols of elements and name elements given their symbols
11.
Describe what happens during a chemical change
12.
ID four possible clues a chemical change has occurred
13.
Apply the Law of Conservation of Mass to chemical reactions
"More than 300 years ago, in 1669, Hennig Brand, a Hamburg alchemist, like
most chemists of his day, was trying to make gold. He let urine stand for
days in a tub until it putrefied. Then he boiled it down to a paste, heated
this paste to a high temperature, and drew the vapors into water where
they could condense - to gold. To his surprise and disappointment,
however, he obtained instead a white, waxy substance that glowed in the
dark. Brand had discovered phosphorus, the first element isolated other
than the metals and non-metals, such as gold, lead and sulphur, that were
known to the ancient civilizations. The word phosphorus comes from the
Greek and means light bearer."
A.D.F. Toy and E.N. Walsh, Phosphorus
chemistry in everyday living, 2nd. ed.
(Washington: ACS, 1987)
2.1 Properties of Matter
Describing Matter
Characteristic Property - a specific set of observable,
measurable traits which distinguish one substance
from another
Extensive Properties – Depends on the amount of
matter in a sample
-Volume is a measure of space occupied by an object
-Mass is the amount of matter an object contains

Intensive Property – depends on the type of matter in a sample,
NOT the amount of matter (ie. Density, color, structure,
melting, boiling)

Identifying Substances
Matter that has a uniform and definite composition is called a
substance
Physical Property – a quality or condition of a substance that
can be observed or measured without changing the
substances composition.

Physical Property?
1.
35.4 kg
2.
Easily broken
3.
Highly Combustible
States of Matter
The three states of matter we will discuss are
solid, liquid, and gas. Each have their own
characteristics.
Solids - Have a definite shape and volume.
Particles are tightly packed together
Liquids – have a definite volume but no definite
shape. Particles are packed more loosely.
Gasses – Indefinite shape and volume. Can be
compressed! Particles move around freely.

Gas and Vapor. Difference?

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The term gas is used for substances such as
oxygen which are in the gaseous state at room
temperature.
Vapor describes the gaseous state of a
substance that is generally a solid or a liquid
at room temperature.
Plasma is a fourth state of matter which
encompasses gasses under certain conditions
Physical Changes
Properties of the material change, but
composition stays the same.
 Can be classified as reversible or irreversible.
Examples?
1. Ice melting
2. Tearing paper

2.2 Mixtures
A mixture is a physical blend of two or more
components.
 Heterogeneous mixture - the composition is NOT
uniform throughout. (ie. Chicken Soup)
 Homogeneous mixture – the composition is
uniform. Also called a Solution. (ie. Ink, air,
stainless steel) NO SPECIFIC DEFINITION OR
RECIPE
 Phase – any part of a sample with uniform
composition and properties.
A well settled mixture of oil and vinegar would have
how many phases? Any homogenous mixture?
Interface – where two phases meet

Separating Mixtures
Differences in physical
properties can be used to
separate mixtures.
-Filtration is the process that
separates a solid form a
liquid in a heterogeneous
mixture.
-Distillation is used to
separate a liquid mixture
of multiple liquids with
different boiling points

Distillation
-Flotation separates mixtures of insoluble solids
with varying densities
-Fractional Crystallization separates mixtures
of soluble solids which form different crystal
shapes
-Chromatography separates mixtures of
dissolved substances based on polarity
2.3 Elements and Compounds


An element is the simplest
form of matter that has a
unique set of properties.
HAS A DEFINITION
(symbol)
A compound is two or
more elements chemically
combined in a fixed
proportion. HAS A
DEFINITION (formula)
Breaking Down Compounds
Compounds can be broken down
into its constituent substances by
chemical means.
 Elements can NOT be broken
down by ordinary chemical
means.
In order to break down compounds a
Chemical Change, or a change
that produces matter with a
different composition than the
original matter, must occur.

Sugar  Carbon + Water
Δ
Compound

1.
2.
3.
Element
Compound
Properties of compounds are completely
different than the components that make
them up.
NaCl
C6H12O6
H2O
Distinguishing Substances and
Mixtures


If the composition of a
material is fixed the
material is a substance.
If the composition of a
material varies the
material is a mixture.
Element
Matter
Substance
Compound
Mixture
Homogeneous Heterogeneous
Mixture
Mixture
Symbols and Formulas


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Chemical Symbols are used by the scientific
community to represent each element. Each
symbol may be one or two letters
Jons Jacob Berzelius created the system we
use today, based on Latin names of elements.
The first letter is always capitalized (W)
The second, when used is always lowercase
(Na)
Chemical Formulas are used to represent
compounds (NaCl)
2.4 Chemical Reactions
Chemical Changes
-Words that usually indicate
chemical change; produce,
burn, rot, rust, decompose,
ferment, explode, corrode, and
sometimes bubble
The ability of a substance to
undergo chemical change is
called a Chemical Property.
During a chemical change the
composition of matter
ALWAYS changes. (not the
case for physical change)

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A chemical change is also called a Chemical
Reaction
During a chemical reaction one or more
substances change into one or more new
substances.
A Reactant is a substance present at the start
of a reaction.
A Product is a substance that is produced in
the reaction.
How do I know if a chemical reaction
is taking place?
There are several possible indicators of a chemical
reaction.
1.
Change in color
2.
Evolution of a gas
3.
Formation of a precipitate, a solid settling from a
liquid
4.
Emission of energy (heat, cold, or light)
*Energy is always involved in chemical reactions*

The Law of Conservation of Mass


During any chemical reaction, the mass of
the products is always equal to the mass of
the reactants.
Therefore, mass cannot be created or
destroyed.
What is Energy?
Energy is the ability to do work or cause change.
Types of energy include

Heat - Measured by changes in temperature, released by
burning

Mechanical - KINETIC = energy of motion, and
POTENTIAL = energy of position (stored energy)

Electrical - based on a flow of electrons (e-'s)

Chemical - a kind of potential energy, used in bonding, etc.

Radiant - all of the "waves": X-ray, radio, TV, microwave,
solar,
light, UV, IR…

Nuclear - energy stored in the nucleus of the atom,
fission/fusion

Law of Conservation of Energy
Energy can be converted from one form to
another but cannot be created or
destroyed.
 The terms matter and energy are
interchangeable as theorized by Einstein
 E=mc2
The amount of energy is directly proportional to
the mass of body
