Download The Periodic Table

The Periodic Table
• The Periodic Table is used to organize the 114 elements
in a meaningful way.
• As a consequence of this organization, there are periodic
properties associated with the periodic table.
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Natural States of the Elements
• Most elements are very reactive.
• Elements are not generally found in
uncombined form.
– Exceptions are:
• Noble metals – gold, platinum and silver
• Noble gases – Group 18
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The Periodic Table
• Columns in the periodic table are called groups
(numbered from 1A to 8A or 1 to 18).
• Rows in the periodic table are called periods.
• Metals are located on the left hand side of the periodic
table (most of the elements are metals).
• Non-metals are located in the top right hand side of the
periodic table.
• Elements with properties similar to both metals and nonmetals are called metalloids and are located at the
interface between the metals and non-metals.
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Reading the Periodic Table - The Basics
Families or groups – vertical columns
- have similar properties
- contain the same outer electron
configuration
- show similar chemical behavior because it
is the outer electrons involved in
chemical reactions
- 18 groups
- Various ways of labeling and naming
Roman numerals + letter (European)
Arabic numerals + letter (American)
Arabic numerals 1-18 (IUPAC)
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The Periodic Table
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The Periodic Table
• Some of the groups in the periodic table are given special
names.
• These names indicate the similarities between group
members:
Group 1: Alkali metals.
Group 2: Alkaline earth metals.
Group 16: Chalcogens.
Group 17: Halogens.
Group 18: Noble gases.
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Families and Groups (cont.)
Representative or Main Group Elements
= Groups 1,2 and 13-18
Transition metals = Groups 3-12
Inner transition elements (metals) =
Element #’s 57-71 (Lantanides) and
Element #’s 89-103 (Actinides)
Periods = Horizontal rows #’d 1-7
Each period contains more and more
elements
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The Periodic Table with the Inner Transition Elements in Place
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Metals
- Found on the left side of the periodic table
Includes: All of groups 1 (except H) and 2,
also Al (but not B) in group 13.
All of the transition elements.
The elements to the right of the transition
elements
The lanthanides and actinides (inner transition metals)
Metals tend to lose electrons!
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Metallic Properties:
Luster: most metals have a silvery white
“metallic” color because they reflect
light of all wavelengths.
Ductile, (capable of being drawn out into
a wire)
Malleable (can be hammered into thin
sheets)
Most semisolids @ room Tº
High electrical conductivity & thermal
conductivity
- Examples: sodium, calcium, gold, aluminum
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Nonmetals
• Found on the right side of the periodic table
• Nonmetals tend to gain electrons!
• Nonmetallic Properties:
–
–
–
–
–
Poor reflectors of light,
Hard or brittle, some are gases or soft solids
Not malleable or ductile
Do not conduct electricity,
Poor conductor of heat
- Examples: carbon, bromine, chlorine, sulfur
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Diatomic Nonmetals
• Diatomic Molecules
Nitrogen gas contains
N2 molecules.
Oxygen gas contains
O2 molecules.
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Metalloids or Semimetals
• Found along jagged line on table
• Metalloids lose or gain electrons depending
on "who they're with!“
• Mixture of both types of properties, or
intermediate type
Examples: B, Si, Ge, As, Sb, Te, At
(the only metals on the solid "semimetal" line are
Al and Po)
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Information in an Element’s “Box” on
the Periodic Table
• Atomic Number = the number of protons
• Atomic Mass = Weighted average of all of
the isotopes of the element
• Mass number (for a particular isotope) = #
protons + # o f neutrons.
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Introduction to the Modern
Concept of Atomic Structure
Comparing the Parts of an Atom
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Comparing Subatomic Particles
Fundamental
Particles
Charge
Location
Mass (grams)
Mass (amu)
Electron
Proton
Neutron
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Atomic Mass and Formula Mass
• To calculate the mass of
a sample of atoms
– Each element exists
as a mixture of
isotopes
– Use a “weighted
average” for the
atomic mass
• Number on the bottom of
each square in the
periodic table is the
average weight of all the
isotopes of an element
• (in amu)
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Atomic Mass and Formula Mass
• Atomic masses are
determined on a
relative scale
• The standard scale
references the
carbon-12 isotope =
12.000 amu
• All other atomic
masses are
determined relative to
carbon-12
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Atomic Mass Units
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Isotopes
• Isotopes are atoms with the same number
of protons but different numbers of
neutrons.
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Isotopes
• A particular isotope is represented by the
symbol.
Only use this symbol when you know the number of neutrons exactly.
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Atomic Mass
Na
22.99
 Listed on the periodic table
 Gives the mass of “average” atom of each
element compared to 12C
 Average atom based on all the isotopes and their
abundance %
 Atomic mass is not a whole number
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Calculating Atomic Mass
 Percent(%) abundance of isotopes
 Mass of each isotope of that element
 Weighted average =
mass isotope1(%) + mass isotope2(%) + …
100
100
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Calculating #s’s of Subatomic Particles;
Protons, Neutrons and Electrons
• The atomic number = the number of
protons.
• If the atom is neutral, the number of
electrons equals the number of protons
• Mass number of an isotope = Protons +
Neutrons therefore Mass # - Atomic
number = # neutrons.
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More Atomic Symbols
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O
8
8 p+
8n
8 e-
65
P
Zn
15
30
15 p+
16 n
15 e-
30 p+
35 n
30 e28
Ions – Charged Particles
• Atoms can form ions by gaining or losing
electrons.
Metals tend to lose one or more electrons
to form positive ions called cations.
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Ions – Charged Particles
• Nonmetals tend to gain one or more
electrons to form negative ions called
anions.
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Isotopes
Cobalt - 59
•
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Helium - 4
•
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Ions
Ion Charges and the Periodic Table
• The ion that a particular atom will form can be predicted
from the periodic table.
– Elements in Group 1 and 2 form 1+ and 2+ ions,
respectively
– Group 7 atoms form anions with 1- charges
– Group 6 atoms form anions with 2- charges
• when compared to the neutral atoms
– Cations have fewer electrons than protons
– Anions have extra electrons (more) than protons
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Common Monatomic Ions
EOS
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