Mendeleev’s Periodic Table of Elements

In 1869, Russian chemist Dmitri Mendeleev (1834-1907) proposed the first widely recognised periodic table of elements.  He developed his table to illustrate periodic trends in the properties of the then-known elements.  Mendeleev also predicted some properties of then-unknown elements that would be expected to fill the gaps in this table.  Most of his predictions were proved correct when the elements in question were subsequently discovered.

Mendeleev’s periodic table has since been expanded and refined with the discovery or synthesis of further new elements and the development of new theoretical models to explain their physical and chemical behaviour.

Atomic Numbers

From atomic numbers 1 (hydrogen) to 118 (ununoctium), all elements have been discovered or reportedly synthesised, including recently-discovered elements 113, 115, 117, and 118.

The first 98 elements exist naturally although some are found only in trace amounts and were initially discovered by synthesis in laboratories.  Elements with atomic numbers from 99 to 118 have only been synthesised, or claimed to be so, in laboratories. Production of elements having higher atomic numbers is being pursued, with the question of how the periodic table may need to be modified to accommodate any such additions being a matter of ongoing debate. Numerous synthetic radio-nuclides of naturally occurring elements have also been produced in laboratories.

Name	Symbol	Atomic #	Appearance	Feature
Hydrogen	H	1		At the Heart of the Hydrogen Atom... Olivine ? Squeezing Hydrogen from Stone and Capturing Carbon
Helium	He	2		Helium - Lighter than Air
Lithium	Li	3		Salted Earth - At one Corner of the Lithium Triangle
Beryllium	Be	4
Boron	B	5
Carbon	C	6		Graphite to Graphene? in a Kitchen Blender
Nitrogen	N	7		Nitrogen - Nature\'s Explosive Building Blocks
Oxygen	O	8
Fluorine	F	9
Neon	Ne	10
Sodium	Na	11
Magnesium	Mg	12
Aluminium	Al	13
Silicon	Si	14
Phosphorus	P	15
Sulfur	S	16
Chlorine	Cl	17
Argon	Ar	18
Potassium	K	19
Calcium	Ca	20		Yes, Calcium is a Metal!
Scandium	Sc	21
Titanium	Ti	22
Vanadium	V	23
Chromium	Cr	24
Manganese	Mn	25
Iron	Fe	26
Cobalt	Co	27
Nickel	Ni	28
Copper	Cu	29		Fuelling our Lust for Copper - Mining in Afghanistan...
Zinc	Zn	30
Gallium	Ga	31
Germanium	Ge	32
Arsenic	As	33
Selenium	Se	34
Bromine	Br	35
Krypton	Kr	36
Rubidium	Rb	37		The Bizarre Behaviour of Negative Mass
Strontium	Sr	38
Yttrium	Y	39
Zirconium	Zr	40
Niobium	Nb	41
Molybdenum	Mo	42
Technetium	Tc	43
Ruthenium	Ru	44
Rhodium	Rh	45
Palladium	Pd	46
Silver	Ag	47
Cadmium	Cd	48
Indium	In	49
Tin	Sn	50		Little Tin Soldiers of Indonesia
Antimony	Sb	51
Tellurium	Te	52
Iodine	I	53
Xenon	Xe	54
Caesium	Cs	55
Barium	Ba	56
Lanthanum	La	57
Cerium	Ce	58
Praseodymium	Pr	59
Neodymium	Nd	60
Promethium	Pm	61
Samarium	Sm	62
Europium	Eu	63
Gadolinium	Gd	64
Terbium	Tb	65
Dysprosium	Dy	66
Holmium	Ho	67
Erbium	Er	68
Thulium	Tm	69
Ytterbium	Yb	70
Lutetium	Lu	71
Hafnium	Hf	72
Tantalum	Ta	73
Tungsten	W	74
Rhenium	Re	75
Osmium	Os	76
Iridium	Ir	77
Platinum	Pt	78
Gold	Au	79
Mercury	Hg	80		Mercury: Beautiful Poison
Thallium	Tl	81
Lead	Pb	82
Bismuth	Bi	83
Polonium	Po	84
Astatine	At	85
Radon	Rn	86
Francium	Fr	87
Radium	Ra	88
Actinium	Ac	89
Thorium	Th	90		Building The Energy Future with Thorium in the Gobi Desert, China
Protactinium	Pa	91
Uranium	U	92
Neptunium	Np	93
Plutonium	Pu	94
Americium	Am	95
Curium	Cm	96
Berkelium	Bk	97
Californium	Cf	98
Einsteinium	Es	99
Fermium	Fm	100
Mendelevium	Md	101
Nobelium	No	102
Lawrencium	Lr	103
Rutherfordium	Rf	104
Dubium	Db	105
Seaborgium	Sg	106
Bohrium	Bh	107
Hassium	Hs	108
Meitnerium	Mt	109
Darmstadtium	Ds	110
Roentgenium	Rg	111
Copernicium	Cn	112
Ununtrium	Uut	113		You Wait Ages for a Chemical Element, and Then? BINGO!!
Flerovium	Fl	114
Ununpentium	Uup	115		You Wait Ages for a Chemical Element, and Then? BINGO!!
Livermorium	Lv	116
Ununseptium	Uus	117		You Wait Ages for a Chemical Element, and Then? BINGO!!
Ununoctium	Uuo	118		You Wait Ages for a Chemical Element, and Then? BINGO!!