This is a typical display of the periodic table of the elements and contains the symbol and atomic number of each element. The periodic table of the chemical elements is a tabular method of displaying the chemical elements. Although precursors to this table exist, its invention is generally credited to Russian chemist Dmitri Mendeleev in 1869. Mendeleev intended the table to illustrate recurring ("periodic") trends in the properties of the elements. The layout of the table has been refined and extended over time, as new elements have been discovered, and new theoretical models have been developed to explain chemical behavior.^[1]

The periodic table is now ubiquitous within the academic discipline of chemistry, providing an extremely useful framework to classify, systematize and compare all the many different forms of chemical behavior. The table has also found wide application in physics, biology, engineering, and industry. The current standard table contains 117 elements as of 27 January 2008 (while element 118 has been synthesized, element 117 has not). However, only the first 112 elements are officially confirmed by the IUPAC, as of June 2009^[2].

[edit] Table

Group #	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18
Period
1	1 H																	2 He
2	3 Li	4 Be											5 B	6 C	7 N	8 O	9 F	10 Ne
3	11 Na	12 Mg											13 Al	14 Si	15 P	16 S	17 Cl	18 Ar
4	19 K	20 Ca	21 Sc	22 Ti	23 V	24 Cr	25 Mn	26 Fe	27 Co	28 Ni	29 Cu	30 Zn	31 Ga	32 Ge	33 As	34 Se	35 Br	36 Kr
5	37 Rb	38 Sr	39 Y	40 Zr	41 Nb	42 Mo	43 Tc	44 Ru	45 Rh	46 Pd	47 Ag	48 Cd	49 In	50 Sn	51 Sb	52 Te	53 I	54 Xe
6	55 Cs	56 Ba	*	72 Hf	73 Ta	74 W	75 Re	76 Os	77 Ir	78 Pt	79 Au	80 Hg	81 Tl	82 Pb	83 Bi	84 Po	85 At	86 Rn
7	87 Fr	88 Ra	**	104 Rf	105 Db	106 Sg	107 Bh	108 Hs	109 Mt	110 Ds	111 Rg	112 Uub	113 Uut	114 Uuq	115 Uup	116 Uuh	(117) (Uus)	118 Uuo
* Lanthanoids			57 La	58 Ce	59 Pr	60 Nd	61 Pm	62 Sm	63 Eu	64 Gd	65 Tb	66 Dy	67 Ho	68 Er	69 Tm	70 Yb	71 Lu
** Actinoids			89 Ac	90 Th	91 Pa	92 U	93 Np	94 Pu	95 Am	96 Cm	97 Bk	98 Cf	99 Es	100 Fm	101 Md	102 No	103 Lr

This common arrangement of the periodic table separates the lanthanoids and actinoids from other elements. The wide periodic table incorporates the f-block. The extended periodic table adds the 8th and 9th periods, incorporating the f-block and adding the theoretical g-block.

Colors in the periodic table show element categories Metals Metalloids Nonmetals Alkali metals Alkaline earth metals Inner transition elements Transition elements Other metals Other nonmetals Halogens Noble gases Lanthanoids Actinoids (Unknown type)
Atomic number colors show state at standard temperature and pressure (0 °C and 1 atm) Solids Liquids Gases Unknown	Borders show natural occurrence Primordial From decay Synthetic (Undiscovered)

[edit] See also

• Periodic table
• Periodic table (block)
• Periodic table (wide)
• Periodic table (extended)
• Alternative Periodic Tables
• Table of nuclides

[edit] References

1. ^ "The periodic table of the elements". International Union of Pure and Applied Chemistry. 2007-07-22. http://www.iupac.org/didac/Didac%20Eng/Didac01/Content/S01.htm. Retrieved 2008-02-08. 
2. ^ Ununbium's discovery (by the German GSI) was officially confirmed in May 2009, so it is now eligible for a permanent name.

v • d • e Periodic tables Layouts Standard · Inline f-block · Vertical · Full names · Names and atomic weights · Text for last · Large table · Metals and nonmetals · Blocks · Valences · Extension beyond the 7th period · Electron configurations · Atomic weights · Electronegativities · Alternatives · Crystal structure Lists of elements by Name · Atomic symbol · Atomic number · Atomic weight · Name etymology (after places, after people) · Discovery Boiling point · Melting point · Density · Oxidation state · Abundance (in humans) · Nuclear stability · Hardness Groups 1 (Alkali metals) · 2 (Alkaline earth metals) · 3 · 4 · 5 · 6 · 7 · 8 · 9 · 10 · 11 · 12 · 13 (Boron group) · 14 (Carbon group) · 15 (Pnictogens) · 16 (Chalcogens) · 17 (Halogens) · 18 (Noble gases) Periods 1 · 2 · 3 · 4 · 5 · 6 · 7 · 8 Other element categories Metals · Transition metals (1st row) · Metalloids · Nonmetals · Lanthanoids · Actinoids · Rare earth elements · Platinum group metals (PGMs) · Post-transition metals Blocks s-block · p-block · d-block · f-block