Download - Periodic table intro2
PERIODIC TABLE &
PERIODIC TRENDS
Organize the following classes into categories.
Chemistry 101 Marketing 214 Art 323
Music 211 Physics 404 Speech 105
Calligraphy 324 Biology 324 Phys Ed 010
Astronomy 212 Economics 103 Sculpture 102
Writing 462 Finance 321 Poetry 209
English 104 Phys. Ed 005 Business 412
Where did the Periodic Table come from?
• 1829– J.W. Dobereiner
• Triad Classification
• 1864– John Newlands
• Law of Octaves
• 1869– Dmitri Mendeleev
• Credited with modern Periodic Table
Still Not Perfect
PotassiumAtomic Mass: 39.10 amu• Highly reactive Metal
ArgonAtomic Mass: 39.95 amu• Inert gas
*Important fact you may want to right down*
The Modern Periodic Table is based on atomic number and electron configuration, not atomic mass.
Periodic Law
• When elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties.
Ya’ll best line up d’em elements in order of increasing proton number
to pick out the properties!
METALS
• Have only a few electrons in outer most energy level.
• Lose e- to form positive ions (X+)
• Good Conductors• Malleable (sheets)• Ductile (wire)• Often Lusterous
NONMETALS
• More than 3 e- in their outermost orbit
• Gain electrons to form negative ions (X-)
• Dull in appearance• Brittle
METALLOIDS• Have properties of metals & nonmetals• Positioned on metal / nonmetal line• B, Si, Ge, As, Sb, Te, Po, At
A Groups = Main Group Elements
AL
KA
LI
AL
KA
LIN
E E
AR
TH
NO
BL
E G
AS
ES
HA
LO
GE
NS
CH
AL
CO
GE
NS
IA IIA VIAVIIA VIIIA
IB – VIIIBTRANSITION METALS
INNER TRANSITION METALS(Lanthanide & Actinide Series)
VAIVAIIIA
3B 4B 5B 6B 7B 8B 1B 2B
Coinage Metals
Pick a Trend, Any Trend
1. Atomic Size
2. Ionization Energy
3. Electron Affinity
4. Electronegativity
Atomic Radius:
No definite shape, but scientist can get a rough measure.
Atomic SizeIt doesn’t depend on Weight Watchers
Ionization Energy
The energy required to remove an electron from an atom in the gas phase.
A(g) + Energy A+(g) + e-
Ionization energy measures how tightly an electron is held in the atom.
Ionization Energy (cont.)
• More and more energy is required to move each electron from an atom
• Metals generally have low IE.
• Nonmetals have high IE.
• IE increases as you move across a period and decreases as you go down a group or family.
Electron AffinityEA – It’s NOT a clothing company
• The energy used or released for a gaseous atom to gain an electron.
A(g) + e- A-(g) + Energy
Electron Affinity (cont.)
In general. . . • EA increases (becomes more negative) as you go across a
period and decreases as you go down a group or family.
• The greater the electron affinity, the greater the IE.– Metals have lower EAs– Nonmetals have higher EAs
Electronegativity
A comparative scale relating the abilities of elements to attract electrons when their atoms are combined.
• Active metals (IA) have the lowest Ens
• Most nonmetals have the highest Ens
And Now a guest appearance by Mr. Tom Lehrer