The periodic table

1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18
1 H 1.0079																	2 He dad
3 Li 6.941	4 Be 9.0122											5 B 10.811	6 C 12.011	7 N 14.007	8 O 15.999	9 F 18.998	10 Ne 20.18
11 Na 22.990	12 Mg 24.305											13 Al 26.982	14 Si 28.086	15 P 30.974	16 S 32.066	17 Cl 35.453	18 Ar 39.948
19 K 39.098	20 Ca 40.078	21 Sc 44.956	22 Ti 47.867	23 V 50.942	24 Cr 51.996	25 Mn 54.938	26 Fe 55.845	27 Co 58.933	28 Ni 58.693	29 Cu 63.546	30 Zn 65.39	31 Ga 69.723	32 Ge 72.81	33 As 74.922	34 Se 78.96	35 Br 79.304	36 Kr 83.80
37 Rb 85.468	38 Sr 87.62	39 Y 88.906	40 Zr 91.224	41 Nb 92.906	42 Mo 95.94	43 Tc 97.907	44 Ru 101.07	45 Rh 102.91	46 Pd 106.42	47 Ag 107.87	48 Cd 112.41	49 In 114.82	50 Sn 118.71	51 Sb 121.76	52 Te 127.60	53 I 126.90	54 Xe 131.29
55 Cs 132.91	56 Ba 139.33	57* La 138.91	72 Hf 178.49	73 Ta 180.95	74 W 183.84	75 Re 186.21	76 Os 190.23	77 Ir 192.22	78 Pt 195.08	79 Au 196.97	80 Hg 200.59	81 Tl 204.38	82 Pb 207.2	83 Bi 208.98	84 Po [208.98]	85 At [209.99]	86 Rn [222.02]
87 Fr [223.02]	88 Ra [226.03]	89* Ac [227.03]	104 Rf [263.11]	105 Db [262.11]	106 Sg [266.12]	107 Bh [264.12]	108 Hs [269.13]	109 Mt [168.14]

58 Ce 140.12

59 Pr 140.91

60 Nd 144.24

61 Pm [144.91]

62 Sm 150.36

63 Eu 151.96

64 Gd 157.25

65 Tb 158.93

66 Dy 162.50

67 Ho 164.93

68 Er 167.26

69 Tm 168.93

70 Yb 173.04

71 Lu 174.97

90 Th 232.04

91 Pa 231.04

92 U 238.03

93 Np [237.05]

94 Pu [244.06]

95 Am [243.06]

96 Cm [247.07]

97 Bk [247.07]

98 Cf [251.08]

99 Es [252.08]

100 Fm [257.10]

101 Md [258.10]

102 No [259.10]

103 Lr [262.11]

Nonmetals	Alkaline Metals	Alkaline-Earth Metals	Transition Metals	Poor Metals
Metalloids	Halogens	Noble Gases	Lanthanoids	Actinoids

Cells with text in red are gaseous at room temperature.
Cells with text in green are liquid at room temperature.
Cells with text in black are solid at room temperature.
Cells with a dashed red outline are not found naturally on earth.
Elements 43, 61, and 84 and greater are only known as radioactive.

Subject classification: this is a chemistry resource .

How to use this periodic table

The periodic table lists all the known elements. It is a useful tool for identifying trends and properties of them. Some things of interest to chemists are:

• Electronegativity
• Ionization energy
• Acidity of oxides
• Atomic radius
• Ionic radius

Groups and Periods

The periodic table is arranged into groups or columns, and periods or rows.

Groups

Elements in the same group, or family, have similar properties. Elements from the same group are found in vertical columns. Some groups are given non-scientific names, such as the halogens, noble gases, alkaline metals, and the alkaline-earth metals. Elements in the same group act similarly because they have the same valence electron configuration.

Periods

Each period represents the filling up of orbitals generated by the principal quantum number.

Non-metals

Non-metals are found on the top-right corner of the p-block elements. These elements tend to gain electrons when forming a bond with metals, or share electron between two non-metals to form a covalent bond. The boxes are also skyblue in colour

Alkaline Metals

Alkaline metals are known as the most reactive metals. This can be observed by their reaction with water, for example. Their reactivity is attributed to the low ionization energy of the outermost electron in the atom. Their most common oxidative state is +1.they tend to lose 1 electron to complete their outer shells whatever.

Alkaline-Earth Metals

Alkali-Earth Metals have the second lowest ionization energy. Their most common oxidation state is +2

Transition Metals

The atoms of the transition metals have more complicated electron arrangements than other atoms. The d orbitals of these elements are being filled. This group contains many well known metals, such as iron (Fe), nickel (Ni), copper (cu), mercury (Hg), and Gold (Au).

Poor Metals

The poor metals consist of aluminum, gallium, indium, thallium, tin, lead, and bismuth.

Metalloids

Metalloids roughly form a staircase line in the periodic table. This line divides metals and nonmetals. The elements around this partition have intermediate metal- and non-metal-like properties. Many of them can be used as semiconductors.

Halogens

All halogens are missing just one electron to fill their valence electron shell. For this reason, in most chemical reactions, halogens tend to gain one electron. halogens always exists as diatomic molecules. Going down the group, the color of elements increase; due to decreasing effective nuclear charge, atomic radius increase and electronegativity decreases. Halogens are not always in -1 oxidation state; when reacting with other more electronegative atoms, they give positive oxidation states. Examples are Cl₂O₇, and BrO^-.

Noble Gases

The noble gases have a full valence electron shell. For this reason, noble gases do not normally react with other elements, hence their former title inert gases. In fact, until 1962, they were thought completely nonreactive. This group consists of the elements helium, neon, argon, krypton, and xenon. They all are colorless gases (nonmetals). If you look at any periodic table, the density of the the noble gases increase as you go downwards. This is because the mass of the atoms gets larger.

Lanthanoids

Lanthanoids are the first elements to have electrons in an f orbital. Electrons are added to the f orbital to create the next element until element number 72, Hafnium.

Actinoids

The actinoids are radioactive elements. Their radioactivity is due to the fact that any nucleus with greater than 82 protons cannot be stable. They are related to the lanthanoids. The actinoids are the second groups of elements to add electrons to the f orbital.

Unknown

There are some unknown elements on the periodic table. However, due to the understanding of periodic table positions their descriptions can be estimated.

Fun Facts

• Iridium and Osmium have the greatest density
• Francium is the least electronegative element and Fluorine is the most electronegative element

See Also

• w:The Periodic Table