Transcript Hein and Arena

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Matter Defined
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• Matter is anything that has mass
and occupies space.
• Matter can be invisible.
• Matter appears to be continuous and
unbroken.
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Physical States of
Matter
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Physical Properties of Solids,
Liquids, and Gases
State
Shape
Volume
Particles
Compressibility
Solid
Definite
Definite
Tightly packed
Very Slight
Liquid
Indefinite
Definite
Mobile; Cohering
Slight
Gas
Indefinite
Indefinite
Independent
High
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Substances and
Mixtures
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Matter refers to all of the materials that
make up the universe.
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Substance
A particular kind of matter that has a fixed
composition and distinct properties.
Examples
ammonia, water, and oxygen.
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Homogeneous Matter
Matter that is uniform in appearance
and with uniform properties throughout.
Examples
ice, soda, solid gold
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Heterogeneous Matter
Matter with two or more physically
distinct phases present.
Examples
wood, blood
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Phase
A homogenous part of a system separated
from other parts by physical boundaries.
Examples
In an ice water mixture ice is the solid
phase and water is the liquid phase
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Mixture
Matter containing 2 or more substances that
are present in variable amounts. Mixtures
are variable in composition. They can be
homogeneous or heterogeneous.
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Homogeneous Mixture (Solution)
A homogeneous mixture of 2 or more
substances. It has one phase.
Example
Sugar and water. Before the sugar and
water are mixed each is a separate phase.
After mixing the sugar is evenly dispersed
throughout the volume of the water.
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Heterogeneous Mixture
A heterogeneous mixture consists of 2 or
more phases.
Example
Sugar and fine white sand. The amount of
sugar relative to sand can be varied. The
sugar and sand each retain their own
properties.
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Classification of matter: A pure substance is always
homogeneous in composition, whereas a mixture
always contains two or more substances and may
be either homogeneous or
heterogeneous.
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Elements
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An element is a fundamental or
elementary substance that cannot be
broken down into simpler substances
by chemical means
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• All known substances on Earth and
probably the universe are formed by
combinations of more than 100
elements.
• Each element has a number.
– Beginning with hydrogen as 1 the
elements are numbered in order of
increasing complexity.
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• Most substances can be decomposed
into two or more simpler substances.
– Water can be decomposed into hydrogen
and oxygen.
– Table salt can be decomposed into
sodium and chlorine.
• An element cannot be decomposed into
a simpler substance.
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ATOM
• The smallest particle of an element that
can exist.
• The smallest unit of an element that
can enter into a chemical reaction.
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Distribution of
Elements
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• Elements are not distributed equally
by nature.
– Oxygen is the most abundant element in
the human body (65%).
– Oxygen is the most abundant element in
the crust of the earth (49.2%)..
• In the universe the most abundant
element is hydrogen (91%) and the
second most abundant element is
helium (8.75%).
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Distribution of the
common elements
in nature.
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Names of the
Elements
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Sources of Element Names
Greek- • Iodine: from the Greek iodes meaning
Color
violet.
Latin• Fluorine: from the Latin fluere
Property meaning to flow.
German-• Bismuth: from the German
Color
weisse mass meaning white mass.
Location • Germanium: discovered in 1866 by a
German chemist.
Famous- • Einsteinium: named for Albert Einstein.
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Scientist
Symbols of the
Elements
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• A symbol stands for
– the element itself
– one atom of the element
– a particular quantity of the element
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Rules governing symbols of the elements
are:
1. Symbols have either one or
two letters.
2. If one letter is used it is
capitalized.
H carbon
C
hydrogen
3. If two letters are used, only Ba
Ne barium
neon
the first is capitalized.
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50 Common Elements and Their Symbols
Al
aluminum
Cr
chromium
Sb
antimony
Co
cobalt
Ar
argon
Cu
As
arsenic
Ba
Li
lithium
Rn
radon
Mg
magnesium
Rb
rubidium
copper
Mn
manganese
Se
selenium
F
fluorine
Hg
mercury
Si
silicon
barium
Ga
gallium
Ne
neon
Ag
silver
Be
beryllium
Ge
germanium
Ni
nickel
Na
sodium
B
boron
Au
gold
N
nitrogen
Sr
strontium
Br
bromine
He
helium
O
oxygen
S
sulfur
Ca
calcium
H
hydrogen
P
phosphorus
Sn
tin
C
carbon
I
iodine
Pt
platinum
W
tungsten
Cs
cesium
Fe
iron
K
potassium
U
uranium
Cl
chlorine
Kr
krypton
radium
Xe
xenon
Pb
lead
Zn
zinc
Ra
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Metals, Nonmetals
and Metalloids
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Metals
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• Metals are solid at room temperature.
– Mercury is an exception. At room temperature it
is a liquid.
• Metals are good conductors of heat and electricity.
Most elements
are metals
physical
properties
of metals
• Metals are malleable (they can be rolled
or
hammered into sheets).
• Metals have high luster (they are shiny).
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• Metals are ductile (they can be drawn into wires).
• Most metals have a high melting point.
• Metals have high densities
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Nonmetals
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Physical Properties of Nonmetals
• Lack luster (they are dull)
• Have relatively low melting points
• Have low densities.
• Poor conductors of heat and electricity
• At room temperature carbon, phosphorous,
sulfur, selenium, and iodine are solids.
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Metalloids
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Metalloids have properties that
are intermediate between metals
and nonmetals
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The Metalloids
1. boron
2. silicon
3. germanium
4. arsenic
5. antimony
6. tellurium
7. polonium
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Nonmetals
arefound
foundtotothe
theleft
right
metalloids.
Metals are
ofofthethemetalloids
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Compounds
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A compound is a distinct substance that
contains two or more elements combined
in a definite proportion by weight.
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There are two types of compounds:
molecular and ionic.
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Molecules
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A molecule is the smallest uncharged
individual unit of a compound formed by
the union of two or more atoms.
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• A water molecule consists of two
hydrogen atoms and one oxygen atom.
• If it is subdivided the water molecule
will be destroyed and hydrogen and
oxygen will be formed.
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Ionic Compounds
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An ion is a positively or negatively
charged atom or group of atoms.
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A cation is a positively charged ion.
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An anion is a negatively charged ion.
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Ionic compounds are held together by
attractive forces between positively and
negatively charged ions.
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Ionic Compound Formulas
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The actual
Sodium
chloride
chemical
andformulas
other ionic
of ionic
compounds express
consist of
thelarge
smallest
aggregates
whole
of cations
number
ratio
andthat
anions.
exists between these
cations and the anions.
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• The formula NaCl does not mean that
a molecule of NaCl exists.
• The formula NaCl means that the
ratio of sodium to chlorine in a
sodium chloride crystal is one to one.
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The ratio of Na+ to Cl- is 1:1
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Compounds can be classified as molecular or
ionic. Ionic compounds are held together by
attractive forces between their positive and
negative charges. Molecular compounds are
held together by covalent bonds.
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Elements That Exist as
Diatomic Molecules
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A diatomic molecule contains exactly two
atoms of the same or different elements.
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Chemical Formulas
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chemical
formulas
Show the symbols of the atoms
of the elements present in a
compound.
CaCl2
Ca calcium
Cl chlorine
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chemical
formulas
Show the ratio of the atoms of
the elements present in a
compound.
CaCl2
2 Cl
1 Ca
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Rules for Writing
Chemical Formulas
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When a formula contains one atom of an
element the symbol of that element
represents the one atom. The number one
(1) is not used as a subscript.
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NaCl
indicates
the element sodium
(one atom)
indicates
the element chlorine
(one atom)
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When the formula contains more than
one atoms of an element the number of
atoms is indicated by a subscript written
to the right of the symbol of that atom.
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H3PO4
indicates
the element
hydrogen (H)
indicates
the element
oxygen (O)
indicates
4 O atoms
indicates
3 H atoms
indicates
the element
phosphorous (P)
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When the formula contains more than
one of a group of atoms that occurs as a
unit, parentheses are placed around the
group, and the number of units of the
group is indicated by a subscript placed
to the right of the parentheses.
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indicates
the element
barium
indicates two
3phosphate (PO4 )
groups
Ba3(PO4)2
indicates three
Ba atoms
indicates the phosphate group
composed of one phosphorous
atom and four oxygen atoms
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Formulas written as H2O, H2SO4,
Ca(NO3)2 and C12H22O11 show only the
number and kind of each atom contained
in the compound; they do not show the
arrangements of the atoms in the
compound or how they are chemically
bonded to each other.
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