Transcript matterclassification

Properties of Matter
Chemistry I
Matter
 Occupies
space (volume)
 Has a mass
 Is represented by three phases:
Solid (s)
 Liquid (l)
 Gas (g)

General Properties of Matter
SOLID
LIQUID
GAS
COMPRESSIBILITY NONE
NONE
HIGH
RIGIDITY
HIGH
NONE
NONE
FLUIDITY
NONE
HIGH
HIGH
SHAPE
DEFINITE NOT
NOT
DEFINITE DEFINITE
DEFINITE DEFINITE NOT
DEFINITE
VOLUME
Physical Properties of Matter

Characteristics that can be observed or
measured without changing the sample’s
composition.

Extensive Properties: depend upon the amount of
the substance present.


Intensive Properties: independent of the amount
of substance present.


Examples: mass, length, volume
Examples: density, color, state, melting point, boiling point,
texture, conductivity, malleability, ductility
Intensive properties can help identify what an
unknown substance is, extensive cannot.
Chemical Properties of Matter
 A chemical
property relates to a
substances ability to undergo a chemical
change that will change it to a NEW
substance with different properties.

Examples are: alkalinity, acidity,
corrosiveness, ability to react with water,
flammibility
Changes in Matter - Physical
 Are
changes in a substance that does
not involve a change in the identity of the
substance.

Examples: cutting, grinding, any phase
change.
Changes in Matter - Chemical
 A chemical
change is a change in a
chemical property. This is also called a
chemical reaction. A new substance is
formed as a result of a chemical change.

Examples: explode, rust, oxidize, corrode,
tarnish, ferment, burn, rot
 No
matter is lost or gained during a
chemical change. This is called the Law of
Conservation of Mass.
How do you observe a chemical
change?
A
chemical change is evidenced by:
A change in color and/or
 The production of bubbles, indicating a gas
has formed, and/or
 A change in temperature and/or
 Formation of a precipitate (a solid which is
produced when 2 liquid substances are
combined).

A chemical change is represented
by a chemical equation
 A chemical
equation has two basic parts,
the reactants and the products.
Reactants: starting substances
 Products: new substances formed

Reactant + Reactant → Product + Product

H2
+ O2
→
H2O2

Practice Physical/Chemical
Changes

Classify the following as physical or
chemical changes:
1.
2.
3.
4.
5.
6.
7.
8.
Bending a piece of wire
Burning coal
Cooking a steak
Dissolving sugar in water
Cutting grass
Growing grass
Souring of milk
Stretching a rubber band
Law of Conservation of Mass
 Mass
is neither created or destroyed
during a chemical reaction, it is
conserved.
Massreactants = Massproducts
 Mercury (II) oxide yields mercury + oxygen

216 g
=
200 g
+
16 g
Classifying Matter
Matter
Pure Substances
Elements
Compounds
Mixtures
Homogeneous
Heterogeneous
Pure substances
 One
material only
 Has a consistent composition throughout
Elements
 Simplest
form of matter
 Made up of atoms with the same number
of protons
 Cannot be broken into any simpler form
of matter
 Combine in simple whole ratios to form
compounds
 Representative particle is the atom
Elements
Elements
Diatomic
Polyatomic
Monatomic
Monatomic Elements
 Exist
in nature as single atoms
 Most of the elements on the periodic
table are monatomic
Diatomic Elements


Are found in nature as two atoms of the same element
that are chemically joined
These elements, in their pure uncombined form, are
diatomic:








Hydrogen (H2)
Oxygen (O2)
Fluorine (F2)
Bromine (Br2)
Iodine (I2)
Nitrogen (N2)
Chlorine (Cl2)
Remember the first seven common diatomic elements
as: HOFBrINCl
Polyatomic Elements
 Exist
in nature as 3 or more atoms of the
same element found bonded together.

Phosphorus, Carbon, and Sulfur are
polyatomic elements
Atoms combine to make compounds
Diatomic
hydrogen
Diatomic oxygen

Two molecules of hydrogen + one molecule of
oxygen form two molecules of water
Compounds
 One
material made of two or more
elements
 Compounds can be separated by
chemical means (chemical reaction is
required)
Mixtures
 Mixtures
are made up of two or more
substances that are not chemically
combined
 Separation of mixtures is by physical
means
Filtering
 Crystallization
 Distillation/Evaporation if the two
substances have different boiling points

Homogenous Mixtures
Homogeneous Mixtures
Solutions
All homogeneous
mixtures are
solutions
Solutions
 Solutions
exist as a mixture of two or
more substances that are evenly
distributed throughout the entire mixture.
 Solutions are made of two components:
Solute – the substance that dissolves
 Solvent – the dissolving medium. The
solvent is present in greater quantity.

Solutions continued
 Solutions

Solid solutions are known as alloys


Examples of alloys are brass (copper & zinc), bronze
(copper & tin), and pewter (copper, tin, & antimony)
Liquid solutions


can be solid, liquid, or gas phase
Examples: salt water, sugar water, water & alcohol
Gas solutions

Example: air
 Solutions
do not settle or scatter light since
the solute particle is extremely small
Heterogenous Mixtures
Heterogeneous mixtures
Colloids
Suspensions
Heterogeneous mixtures
 The
two or more substances in this
mixtures are not evenly distributed
throughout the substance.
Colloids
– have intermediate particle size
 Can not be filtered
 Scatter light (known as the Tyndall effect)
 Do not settle
 Colloids

Examples: fog, milk, blood, gelatin,
mayonnaise
Tyndall effect

The solute
particles
reflect the
light as it
passes
through
making it
visible.
Suspensions
 Have
a large solute particle
 Scatter light
 Can be separated by filtration
 Solute particles settle if left undisturbed

Examples: Italian salad dressing, muddy
water
Separating Mixtures
 Filtration:
using a porous barrier to
separate a solid from a liquid.
Separating Mixtures
 Distillation:
separation technique that is
based on differences in boiling points of
the substances involved.
Separating Mixtures
 Crystallization:
separation technique
that results in the formation of pure solid
particles of a substance from a solution.
Separating Mixtures
 Chromatography:
technique that
separates the components of a mixture.
Periodic Table
 The
Periodic Table organizes the known
elements in increasing Atomic Number.
 This arrangement creates trends and
groups that can be used to predict
properties of elements.
 Periods go across the table, while
Groups go down the table.
 Groups are also called families and
include: Alkali metals, Alkaline earth
metals, Halogens, Noble gases, and
Transition metals.
Metal, Nonmetals, Metalloids
Periodic Table Groups