the periodic table history. zmemorize the periodic table by mondaymemorize zhistory of the periodic...
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The Periodic Table
History
Memorize the periodic table by Monday
History of the periodic table
Newlsands
John Newlands (1837, English) Law of Octaves (every 8th element was
grouped together) Ordered elements by atomic mass
Mendeleev
Dmitri Mendeleev (1869, Russian) Also organized elements
by increasing atomic mass.
Elements with similar properties were grouped together.
Mendeleev
Dmitri Mendeleev (1869, Russian) Predicted properties of undiscovered
elements.
Moseley
Henry Mosely (1913, British)
Organized elements by increasing atomic number.
Resolved discrepancies in Mendeleev’s arrangement.
This is the way the current Periodic Table is arranged.
Organization of theElements
The Periodic Table
MetalsNonmetalsMetalloids
Metallic Character
Metals
Most of the periodic table is made of metals!
Form positive ions Metals are good conductors of
heat and electricity Metals are malleable Metals are ductile Metals have high tensile
strength Metals have luster
Examples of MetalsExamples of Metals
Potassium, K reacts with water and must be stored in kerosene
Zinc, Zn, is more stable than potassium
Copper, Cu, is a relatively soft metal, and a very good electrical conductor.
Mercury, Hg, is the only metal that exists as a liquid at room temperature
PropertiesProperties of Nonmetalsof Nonmetals
Nonmetals are poor conductors of heat and electricity Nonmetals tend to be brittle Many nonmetals are gases at room temperature
Examples of NonmetalsExamples of Nonmetals
Sulfur, S, was once known as “brimstone”
Microspheres of phosphorus, P, a reactive nonmetal
Graphite is not the only pure form of carbon, C. Diamond is also carbon; the color comes from impurities caught within the crystal structure
PropertiesProperties of of MetalloidsMetalloids
Metalloids straddle the border between metals and nonmetals on the periodic table.
They have properties of both metals and nonmetals.Metalloids are more brittle than metals, less brittle than most nonmetallic solids Metalloids are semiconductors of electricity Some metalloids possess metallic luster
Silicon, Si – A MetalloidSilicon, Si – A Metalloid
Silicon has metallic luster Silicon is brittle like a nonmetal Silicon is a semiconductor of electricity
Other metalloids include: Boron, B Germanium, Ge Arsenic, As Antimony, Sb Tellurium, Te
Metals vs. Nonmetals
Metals Nonmetals
Luster High-shiny Dull
Conductor Good for heat and electricity poor
Malleable Yes-hammered into sheets No-brittle
Ductile Yes-pulled into wires No-brittle
Melting point High Low
Density High low
Chemical Reactivity
Families Similar valence e- within a group result in
similar chemical properties
Chemical Reactivity
Alkali MetalsAlkaline Earth MetalsTransition MetalsHalogensNoble Gases
Periodic Trends
The Periodic Table
0
50
100
150
200
250
0 5 10 15 20Atomic Number
Ato
mic
Ra
diu
s (
pm
)
Periodic Law
When elements are arranged in order of
increasing atomic #, elements with similar
properties appear at regular intervals.
0
50
100
150
200
250
0 5 10 15 20Atomic Number
Ato
mic
Ra
diu
s (
pm
)
Atomic Radius size of atom
© 1998 LOGALFirst Ionization Energy
Energy required to remove one e- from a neutral atom.
© 1998 LOGAL
Melting/Boiling Point
Other Properties
Atomic Radius
0
50
100
150
200
250
0 5 10 15 20Atomic Number
Ato
mic
Ra
diu
s (
pm
)
Atomic Radius
Li
ArNe
KNa
1
2
3
4 5
6
7
Atomic Radius Increases to the LEFT and DOWN
Atomic Radius
Why larger going down?
Higher energy levels have larger orbitals
Shielding - core e- block the attraction between the nucleus and the valence e-
Why smaller to the right?
Increased nuclear charge without additional shielding pulls e- in tighter
Atomic Radius
First Ionization Energy
0
500
1000
1500
2000
2500
0 5 10 15 20Atomic Number
1s
t Io
niz
ati
on
En
erg
y (k
J)
Ionization Energy
KNaLi
Ar
NeHe
1
2
3
4 5
6
7
First Ionization Energy Increases UP and to the RIGHT
Ionization Energy
Why opposite of atomic radius?
In small atoms, e- are close to the nucleus where the attraction is stronger
Why small jumps within each group?
Stable e- configurations don’t want to lose e-
Ionization Energy
Successive Ionization Energies
Mg 1st I.E. 736 kJ
2nd I.E. 1,445 kJ
Core e- 3rd I.E. 7,730 kJ
Large jump in I.E. occurs when a CORE e- is removed.
Ionization Energy
Al 1st I.E. 577 kJ
2nd I.E. 1,815 kJ
3rd I.E. 2,740 kJ
Core e- 4th I.E. 11,600 kJ
Successive Ionization Energies
Large jump in I.E. occurs when a CORE e- is removed.
Ionization Energy
1
2
3
4 5
6
7
Melting/Boiling Point Highest in the middle of a period.
Melting/Boiling Point
Ionic Radius
Cations (+)
lose e-
smaller
© 2002 Prentice-Hall, Inc.
Anions (–)
gain e-
larger
Ionic Radius
Which atom has the larger radius?
Be or Ba
Ca or Br
Ba
Ca
Examples
Which atom has the higher 1st I.E.?
N or Bi
Ba or Ne
N
Ne
Examples
Which atom has the higher melting/boiling point?
Li or C
Cr or Kr
C
Cr
Examples
Which particle has the larger radius?
S or S2-
Al or Al3+
S2-
Al
Examples
Chinese Periodic Table
Periodic TableHydrogen: most abundant gas in the universe, 1 valence electron, often exists as a single proton.
Alkali Metals: 1 valence electron, forms +1 ion, most reactive metals, combine with halogens to form salts. Soft silvery white. Most reactive is at the bottom.
Alkaline Earth Metals: 2 valence electrons, +2 ion
Transition Metals: multiple charges, bright colored, used in building, coins, and jewelry
Halogens: “Salt formers”, 7 valence electrons, -1 ion, most reactive nonmetals
Noble Gases: all have full valence shell of 8 electrons, except He which has 2. Inert (unreactive) gases.
Rare Earth or Inner Transition Metals:
Many synthetic, rare, or radioactive elements. Divided into Lanthanides and Actinides