The Periodic Table of the Elements was perhaps the first time science found a pattern in nature of the kind so often previously postulated by people proposing mystical schemes for organizing the Universe:
H
* * He
Li Be B C N O F Ne
Na Mg Al Si P S Cl Ar
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rb Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mr Ds Rg
After Lawrencium, element 103, elements 104 and 105 were called Un-nil-quadium and Un-nil-pentium, but now elements 104 through 109 are officially named Rutherfordium, Dubnium, Seaborgium, Bohrium, Hassium, and Meitnerium, and apparently the next two elements are known as Darmstadtium and Roentgenium as well.
There are names for the groups of elements in the Periodic Table:
----- Alkali Metals
/ -- Alkaline Earth Metals
| / --- Coinage Metals
| | / He
Li Be | B C N O F Ne
Na Mg | Al Si P S Cl Ar
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rb Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mr Ds Rg | | | | | |
| || | | | | \
\ / | | | | \ --- Inert Gases, Noble Gases
------------------------- Transition Metals ------------------------- | | | \ ------ Halogens
| | \ --------- Chalcogens
| \ ------------ Pnictogens
\ --------------- Tetrels
------------------ Triels, Boron Group Elements
---- Rare Earths: Lanthanides plus Scandium and Yttrium
/
|- Sc
|- Y
- La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu -- Lanthanides
Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr -- Actinides
The lighter halogens are stronger than the heavier ones, whereas the heavier alkali metals are stronger than the lighter ones; that is, they are more reactive.
This is a consequence of a general property of how electronegative and electropositive ions behave chemically, and thus this property tells us about the behavior of elements in other columns of the Periodic Table as well.
Carbon is obviously not a metal; Tin and Lead, on the other hand, have always been recognized as metals, but they're all in the same column in the Periodic Table.
So, while the metals are on the left of the Periodic Table, and the non-metals are on the right, the boundary between them is not vertical but slanted.
Li Be |B ]C N O F Ne Na Mg Al|Si]P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga[Ge|As Se]Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rb Pd Ag Cd In Sn[Sb|Te]I Xe Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi[Po|At]Rn Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mr Ds Rg
There is no universally agreed-upon boundary between metals and nonmetals.
One conventional line includes Aluminum, Germanium, Antimony, and Polonium as metals, and Boron, Silicon, Arsenic, Tellurium, and Astatine as non-metals.
Other chemists include a group of semi-metals or metalloids between the metals and non-metals.
Boron, Silicon, and Astatine are sometimes included in this group, and sometimes classed as non-metals.
Germanium, Arsenic, Antimony, Tellurium, and Polonium are usually included on most lists of semi-metals or metalloids.
Since Selenium is shiny and metallic in appearance, I'm somewhat surprised, despite its position in the Periodic Table in the same column as oxygen and sulfur, that it, too, isn't recognized as a semi-metal.
Also, there were different systems of numerical designation for the columns of the Periodic Table:
IA IIA IVA VIA VIII IB IIIB VB VIIB European, former IUPAC
IIIA VA VIIA IIB IVB VIB 0
1A 2A 3A 4A 5A 6A 7A 8... 8 1B 2B 3B 4B 5B 6B 7B 0
IA IIA IVB VIB VIII IB IIIA VA VIIA American
IIIB VB VIIB IIB IVA VIA VIIIA
1A 2A 3B 4B 5B 6B 7B 8... 8 1B 2B 3A 4A 5A 6A 7A 8A
1 2 3... 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Current IUPAC
H He
Li Be B C N O F Ne
Na Mg Al Si P S Cl Ar
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rb Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mr Ds Rg
Later on, particle physics found a symmetry in the properties of heavy short-lived particles that eventually was explained in terms of the quark model...
and the arrangement of ten items in a triangle was considered to be the holy Tetractys by the Pythagoreans. Another famous set of ways to link ten items together is discussed in the page entitled A Peculiar Deck of Cards
The binary number sequence, now so frequently encountered in connection with computers, also forms the basis of the I Ching or Book of Changes (perhaps more literally, the Change Classic). The order in which the hexagrams are discussed in the I Ching is not the numerical binary order, but the following:
While no simple mathematical rule has been found to account for this complete sequence, it certainly does have many symmetries.
The hexagrams in this sequence are clearly grouped into 32 pairs. In each pair, the second hexagram is usually the result of reversing the sequence of solid and broken lines in the first one; only if the sequence of the first one would be the same when reversed is the second one, instead, inverted from the first one by replacing solid lines with broken lines, and broken lines with solid ones.
The first two hexagrams are all solid lines and all broken lines, and the last two both consist of alternating solid and broken lines.
A Western form of divination based on binary sequences is known as Geomancy; not the Feng Shui of China, but rather the Ilm al-Raml of the Middle East.
Copyright (c) 2005 John J. G. Savard