Semimetals or Semiconductors or Metalloids (B, Si, Ge, As, Se, Sb, Te) have low electrical conductivities which increase with temperature, the opposite to metals. They have some of the properties of  metals and some of the nonmetals. Most have a metallic appearance.

            Nonmetals (H, He, C, N, O, F, Ne, P, S, Cl, Ar, Br, Kr, I, Xe, At, Rn) are basically defined as elements that are not metals. Normally excluding the halogens and the noble gasses since these have a "group" of there own.
           Their chemical properties are generally:
They usually have four to eight valence electrons.
They have high electron affinities. (Except the noble gases)
They are good oxidizing agents. (Except the noble gases)
They have hydroxides which are acidic. (Except the noble gases)
They are electronegative.
           Their physical properties generally include:
They are all insulators (except Carbon (graphite).
They are brittle, not ductile in their solid state.
They show no metallic lustre.
They may be transparent or translucent.
They have low density.
They form molecules which consists of atoms covalently bonded; the noble gases are monatomic.
           Nobel gas (He, Ne, Ar, Kr, Xe, Rn) refers to any element of the group of six elements in group 8 of the periodic table.  They are Argon, Helium, Krypton, Neon, Radon, and Xenon.  Unlike most elements, the noble gases are monatomic. The atoms have stable configurations of electrons, therefore under normal conditions they do not form compounds with other elements.
           They were called inert gases until around 1962 when Xenon tetrafluoride, XeF4, was produced in the laboratory. This was the first report of a stable compound  of a noble gas with another single element. Since then other compounds of noble gasses have been produced, including some compounds of Carbon.
The halogens are the elements in group VII of the periodic table. They are Fluorine, Chlorine, Bromine, Iodine and Astatine.
           The name Halogen (F, Cl, Br, I, At) comes from the Greek Hals(salt) and gen(producing). This is  because the halogens readily react with metals to form salts.
           Generally the halogens are the most reactive group of non-metals. They are strong oxidising agents.
The halogens are so reactive that they cannot exist free in nature, indeed, Fluorine is reactive enough to combine with almost all of the known elements, including some of the noble gasses.
           Elements in Group VI are sometimes known as Chalogens (O, S, Se, Te, Po). The Group consists of Oxygen and  Sulphur (Nonmetals) Selenium and Tellurium (Semiconductors) and Polonium (Radioactive metal). The name of the group is derived from two Greek words meaning Copper and Born. This is because most Copper compounds consist of Copper and one of these elements. Elements with strong affinities for members of this group are called Chalophiles.

Name: Hydrogen
Symbol: H
Atomic Number: 1
Atomic Weight: 1,00794 g/mol
Oxidation States: 1
Boiling Point: 20,28 K
Melting Point: 13,81 K
Density: 0,0899 (Gas 273K g/l)
Electron Configuration: 1s1
Acid/Base Properties: Amphoteric
Crystal Structure: Hexagonal
Electronegativity: 2,10
Heat of Vaporization: 0,4581 kJ/mol
Heat of Fusion: 0,0585 kJ/mol
Thermal Conductivity: 0,1815 W/(m K) (at 300 K)
Specific Heat Capacity: 14,304 J/(g K) (at 300 K)
First Ionization Potential: 13,598
Atomic Volume: 14,10 cm³/mol
Atomic Radius: 2,08 A
Covalent Radius: 0,32 A
Synthetic: No
Discovery: 1766; by Cavendish in London, England
Note: colorless gas, less dense than air, very flammable

Name: Helium
Symbol: He
Atomic Number: 2
Atomic Weight: 4,00260 g/mol
Boiling Point: 4,216 K
Melting Point: 0,95 K
Density: 0,1785 (Gas 273K g/l)
Electron Configuration: 1s2
Crystal Structure: Hexagonal
Heat of Vaporization: 0,084 kJ/mol
Heat of Fusion: 0,021 kJ/mol
Thermal Conductivity: 0,152 W/(m K) (at 300 K)
Specific Heat Capacity: 5,193 J/(g K) (at 300 K)
First Ionization Potential: 24,587
Atomic Volume: 31,80 cm³/mol
Covalent Radius: 0,93 A
Synthetic: No
Discovery: 1895; by Ramsay in London, England
Note: colorless gas, less dense than air, non- flammable; used in blimps

Name: Boron
Symbol: B
Atomic Number: 5
Atomic Weight: 10,811 g/mol
Oxidation States: 3
Boiling Point: 4275 K
Melting Point: 2365 K
Density: 2,34 g/cm³
Electron Configuration: 1s2,2s2,p1
Acid/Base Properties: Acidic
Crystal Structure: Rhombohedral
Electronegativity: 2,04
Heat of Vaporization: 507,8 kJ/mol
Heat of Fusion: 22,6 kJ/mol
Electrical Conductivity: 5x10e-12 10⁶ (Om cm)^-1
Thermal Conductivity: 27,0 W/(m K) (at 300 K)
Specific Heat Capacity: 1,026 J/(g K) (at 300 K)
First Ionization Potential: 8,298
Atomic Volume: 4,60 cm³/mol
Atomic Radius: 0,98 A
Covalent Radius: 0,82 A
Synthetic: No
Discovery: 1808; by Lussac and Davy in London
Note: non-metal; unreactive with water or oxygen; used in detergents, glass making, and fire proof materials

Name: Carbon
Symbol: C
Atomic Number: 6
Atomic Weight: 12,011 g/mol
Oxidation States: +/-4, 2
Boiling Point: 5100 K
Melting Point: 3825 K
Density: 2,26 g/cm³
Electron Configuration: 1s2,2s2,p2
Acid/Base Properties: Acidic
Crystal Structure: Hexagonal
Electronegativity: 2,55
Heat of Vaporization: 715 kJ/mol
Electrical Conductivity: 0,07 10⁶ (Om cm)^-1
Thermal Conductivity: 80-230 W/(m K) (at 300 K)
Specific Heat Capacity: 0,709 J/(g K) (at 300 K)
First Ionization Potential: 11,260
Atomic Volume: 5,30 cm³/mol
Atomic Radius: 0,91 A
Covalent Radius: 0,77 A
Synthetic: No
Discovery: prehistory; by unknown discoverer
Note: non-metal; conducts electric current; found in coal and other hydrocarbons; used in making steel

Name: Nitrogen
Symbol: N
Atomic Number: 7
Atomic Weight: 14,0067 g/mol
Oxidation States: +/-3, 5,4,2
Boiling Point: 77,344 K
Melting Point: 63,15 K
Density: 1,251 (Gas 273K g/l)
Electron Configuration: 1s2,2s2,p3
Acid/Base Properties: Acidic
Crystal Structure: Hexagonal
Electronegativity: 3,04
Heat of Vaporization: 2,7928 kJ/mol
Heat of Fusion: 0,36 kJ/mol
Thermal Conductivity: 0,02598 W/(m K) (at 300 K)
Specific Heat Capacity: 1,042 J/(g K) (at 300 K)
First Ionization Potential: 14,534
Atomic Volume: 17,30 cm³/mol
Atomic Radius: 0,92 A
Covalent Radius: 0,75 A
Synthetic: No
Discovery: 1772; Rutherford; Edinburgh, Scotland
Note: colorless gas; breathable air is 78% nitrogen; used in plastics and fertilizers

Name: Oxygen
Symbol: O
Atomic Number: 8
Atomic Weight: 15,9994 g/mol
Oxidation States: -2
Boiling Point: 90,188 K
Melting Point: 54,8 K
Density: 1,429 (Gas 273K g/l)
Electron Configuration: 1s2,2s2,p4
Crystal Structure: Cubic
Electronegativity: 3,44
Heat of Vaporization: 3,4109 kJ/mol
Heat of Fusion: 0,222 kJ/mol
Thermal Conductivity: 0,2674 W/(m K) (at 300 K)
Specific Heat Capacity: 0,92 J/(g K) (at 300 K)
First Ionization Potential: 13,618
Atomic Volume: 14,0 cm³/mol
Atomic Radius: 0,65 A
Covalent Radius: 0,73 A
Synthetic: No
Discovery: 1774; Priestly ? Scheele; Leeds, France
Note: colorless gas; very reactive with most elements; used in the chemical industry; breathable air is 21% oxygen

Name: Fluorine
Symbol: F
Atomic Number: 9
Atomic Weight: 18,99840 g/mol
Oxidation States: -1
Boiling Point: 85,0 K
Melting Point: 53,65 K
Density: 1,696 (Gas 273K g/l)
Electron Configuration: 1s2,2s2,p5
Crystal Structure: Cubic
Electronegativity: 3,98
Heat of Vaporization: 3,2698 kJ/mol
Heat of Fusion: 0,26 kJ/mol
Thermal Conductivity: 0,0279 W/(m K) (at 300 K)
Specific Heat Capacity: 0,824 J/(g K) (at 300 K)
First Ionization Potential: 17,422
Atomic Volume: 17,10 cm³/mol
Atomic Radius: 0,57 A
Covalent Radius: 0,72 A
Synthetic: No
Discovery: 1886; by Moissan in Paris, France
Note: yellow gas; found in many organic compounds and salts; the most reactive of all chemical elements; used to make plastics and in aluminum production

Name: Neon
Symbol: Ne
Atomic Number: 10
Atomic Weight: 20,1797 g/mol
Boiling Point: 27,10 K
Melting Point: 24,55 K
Density: 0,900 (Gas 273K g/l)
Electron Configuration: 1s2,2s2,p6
Crystal Structure: Cubic, face centered
Heat of Vaporization: 1,77 kJ/mol
Heat of Fusion: 0,34 kJ/mol
Thermal Conductivity: 0,0493 W/(m K) (at 300 K)
Specific Heat Capacity: 1,030 J/(g K) (at 300 K)
First Ionization Potential: 21,564
Atomic Volume: 16,90 cm³/mol
Atomic Radius: 0,51 A
Covalent Radius: 0,71 A
Synthetic: No
Discovery: 1898; Travers ? Ramsay; London
Note: colorless gas; under normal conditions, will not react with any other elements; used in electric signs

Name: Silicon
Symbol: Si
Atomic Number: 14
Atomic Weight: 28,0855 g/mol
Oxidation States: 4,2
Boiling Point: 2630 K
Melting Point: 1683 K
Density: 2,33 g/cm³
Electron Configuration: [Ne]3s2,p2
Acid/Base Properties: Amphoteric
Crystal Structure: Cubic, face centered
Electronegativity: 1,90
Heat of Vaporization: 359 kJ/mol
Heat of Fusion: 50,2 kJ/mol
Electrical Conductivity: 4x10e-4 10⁶ (Om cm)^-1
Thermal Conductivity: 148 W/(m K) (at 300 K)
Specific Heat Capacity: 0,70 J/(g K) (at 300 K)
First Ionization Potential: 8,151
Atomic Volume: 12,1 cm³/mol
Atomic Radius: 1,32 A
Covalent Radius: 1,11 A
Synthetic: No
Discovery: 1824; Berzelius; Stockholm, Sweden
Note: non-metal; common sand is mostly an oxide of silicon, SiO2; used in electronics industry in semiconductors

Name: Phosphorus
Symbol: P
Atomic Number: 15
Atomic Weight: 30,97376 g/mol
Oxidation States: 5, +/-3,4
Boiling Point: 553 K
Melting Point: 317,3 K
Density: 1,82 g/cm³
Electron Configuration: [Ne]3s2,p3
Acid/Base Properties: Acidic
Crystal Structure: Monoclinic
Electronegativity: 2,19
Heat of Vaporization: 12,4 kJ/mol
Heat of Fusion: 0,63 kJ/mol
Electrical Conductivity: 10e-16 10⁶ (Om cm)^-1
Thermal Conductivity: 0,235 W/(m K) (at 300 K)
Specific Heat Capacity: 0,769 J/(g K) (at 300 K)
First Ionization Potential: 10,486
Atomic Volume: 17,0 cm³/mol
Atomic Radius: 1,28 A
Covalent Radius: 1,06 A
Synthetic: No
Discovery: 1669; by Brandt in Hamburg, Germany
Note: soft, non-metal; certain forms are very flammable; used in fertilizers and detergents

Name: Sulfur
Symbol: S
Atomic Number: 16
Atomic Weight: 32,066 g/mol
Oxidation States: 6, +/-2,4
Boiling Point: 717,62 K
Melting Point: 392,2 K
Density: 2,07 g/cm³
Electron Configuration: [Ne]3s2,p4
Acid/Base Properties: Acidic
Crystal Structure: Orthorhombic
Electronegativity: 2,58
Heat of Vaporization: 10 kJ/mol
Heat of Fusion: 1,73 kJ/mol
Electrical Conductivity: 5x10e-16 10⁶ (Om cm)^-1
Thermal Conductivity: 0,269 W/(m K) (at 300 K)
Specific Heat Capacity: 0,710 J/(g K) (at 300 K)
First Ionization Potential: 10,360
Atomic Volume: 15,50 cm³/mol
Atomic Radius: 1,27 A
Covalent Radius: 1,02 A
Synthetic: No
Discovery: prehistory; discoverer unknown
Note: non-metal solid; burns in air; used in many industrial processes; sulfur oxides in the atmosphere create acid rain

Name: Chlorine
Symbol: Cl
Atomic Number: 17
Atomic Weight: 35,4527 g/mol
Oxidation States: +/-1, 3,5,7
Boiling Point: 239,18 K
Melting Point: 172,17 K
Density: 3,214 (Gas 273K g/l)
Electron Configuration: [Ne]3s2,p5
Acid/Base Properties: Acidic
Crystal Structure: Orthorhombic
Electronegativity: 3,16
Heat of Vaporization: 10,20 kJ/mol
Heat of Fusion: 3,21 kJ/mol
Thermal Conductivity: 0,0089 W/(m K) (at 300 K)
Specific Heat Capacity: 0,48 J/(g K) (at 300 K)
First Ionization Potential: 12,967
Atomic Volume: 18,7 cm³/mol
Atomic Radius: 0,97 A
Covalent Radius: 0,99 A
Synthetic: No
Discovery: 1774; by Scheele in Uppsala, Sweden
Note: sharp smelling, yellow-green gas; used to make bleach and plastics; made by decomposition of table salt, sodium chloride

Name: Argon
Symbol: Ar
Atomic Number: 18
Atomic Weight: 39,948 g/mol
Boiling Point: 87,45 K
Melting Point: 83,95 K
Density: 1,784 (Gas 273K g/l)
Electron Configuration: [Ne]3s2,p6
Crystal Structure: Cubic, face centered
Heat of Vaporization: 6,506 kJ/mol
Heat of Fusion: 1,188 kJ/mol
Thermal Conductivity: 0,0177 W/(m K) (at 300 K)
Specific Heat Capacity: 0,520 J/(g K) (at 300 K)
First Ionization Potential: 15,759
Atomic Volume: 24,2 cm³/mol
Atomic Radius: 0,88 A
Covalent Radius: 0,98 A
Synthetic: No
Discovery: 1894; Ramsay ? Rayleigh; London
Note: colorless gas; non-reactive with most other elements; used in light bulbs; 1% of breathable air is argon

Name: Germanium
Symbol: Ge
Atomic Number: 32
Atomic Weight: 72,61 g/mol
Oxidation States: 4
Boiling Point: 3107 K
Melting Point: 1211,5 K
Density: 5,32 g/cm³
Electron Configuration: [Ar]3d10,4s2,p2
Acid/Base Properties: Amphoteric
Crystal Structure: Cubic, face centered
Electronegativity: 2,01
Heat of Vaporization: 334,3 kJ/mol
Heat of Fusion: 31,8 kJ/mol
Electrical Conductivity: 4x10e-4 10⁶ (Om cm)^-1
Thermal Conductivity: 59,9 W/(m K) (at 300 K)
Specific Heat Capacity: 0,32 J/(g K) (at 300 K)
First Ionization Potential: 7,899
Atomic Volume: 13,60 cm³/mol
Atomic Radius: 1,37 A
Covalent Radius: 1,22 A
Synthetic: No
Discovery: 1886; by Winkler in Freiberg, Germany
Note: a semiconductor like silicon; used in high temperature applications where cost is not so important

Name: Arsenic
Symbol: As
Atomic Number: 33
Atomic Weight: 74,9216 g/mol
Oxidation States: +/-3, 5
Boiling Point: 876 (subl.) K
Melting Point: 1090 (28 atm.) K
Density: 5,78 g/cm³
Electron Configuration: [Ar]3d10,4s2,p4
Acid/Base Properties: Acidic
Crystal Structure: Rhombohedral
Electronegativity: 2,18
Heat of Vaporization: 32,4 kJ/mol
Heat of Fusion: 27,7 kJ/mol
Electrical Conductivity: 3,8 10⁶ (Om cm)^-1
Thermal Conductivity: 50 W/(m K) (at 300 K)
Specific Heat Capacity: 0,33 J/(g K) (at 300 K)
First Ionization Potential: 9,81
Atomic Volume: 13,10 cm³/mol
Atomic Radius: 1,39 A
Covalent Radius: 1,20 A
Synthetic: No
Discovery: 1250; by Magnus in Germany
Note: metalloid; reacts easily with oxygen; burns in air; a poison used in insecticides; used as a wood preservative and in glass making

Name: Selenium
Symbol: Se
Atomic Number: 34
Atomic Weight: 78,96 g/mol
Oxidation States: 4, -2,6
Boiling Point: 958 K
Melting Point: 494 K
Density: 4,79 g/cm³
Electron Configuration: [Ar]3d10,4s2,p4
Acid/Base Properties: Acidic
Crystal Structure: Hexagonal
Electronegativity: 2,55
Heat of Vaporization: 26,32 kJ/mol
Heat of Fusion: 5,54 kJ/mol
Electrical Conductivity: 8 10⁶ (Om cm)^-1
Thermal Conductivity: 2,04 W/(m K) (at 300 K)
Specific Heat Capacity: 0,32 J/(g K) (at 300 K)
First Ionization Potential: 9,752
Atomic Volume: 16,50 cm³/mol
Atomic Radius: 1,40 A
Covalent Radius: 1,16 A
Synthetic: No
Discovery: 1817; Berzelius; Stockholm, Sweden
Note: very soft, shiny metal; burns in air; does not react with water; used in photoelectric cells and photocopiers

Name: Bromine
Symbol: Br
Atomic Number: 35
Atomic Weight: 79,904 g/mol
Oxidation States: +/-1, 5,7
Boiling Point: 331,85 K
Melting Point: 265,95 K
Density: 3,12 g/cm³
Electron Configuration: [Ar]3d10,4s2,p5
Acid/Base Properties: Acidic
Crystal Structure: Orthorhombic
Electronegativity: 2,96
Heat of Vaporization: 14,725 kJ/mol
Heat of Fusion: 5,286 kJ/mol
Electrical Conductivity: 10e-16 10⁶ (Om cm)^-1
Thermal Conductivity: 0,122 W/(m K) (at 300 K)
Specific Heat Capacity: 0,266 J/(g K) (at 300 K)
First Ionization Potential: 11,814
Atomic Volume: 23,5 cm³/mol
Atomic Radius: 1,12 A
Covalent Radius: 1,14 A
Synthetic: No
Discovery: 1826; by Balard in Montpellier, France
Note: dark red, sharp smelling liquid; used in fire proofing materials and in photographic chemicals; one of the few chemical elements that are liquid at room temperature

Name: Krypton
Symbol: Kr
Atomic Number: 36
Atomic Weight: 83,80 g/mol
Oxidation States: 0,2
Boiling Point: 120,85 K
Melting Point: 116 K
Density: 1,784 (Gas 273K g/l)
Electron Configuration: [Ar]3d10,4s2,p8
Crystal Structure: Cubic, face centered
Heat of Vaporization: 9,029 kJ/mol
Heat of Fusion: 1,638 kJ/mol
Thermal Conductivity: 0,00949 W/(m K) (at 300 K)
Specific Heat Capacity: 0,248 J/(g K) (at 300 K)
First Ionization Potential: 13,999
Atomic Volume: 32,2 cm³/mol
Atomic Radius: 1,03 A
Covalent Radius: 1,89 A
Synthetic: No
Discovery: 1898; Ramsay ? Travers; London
Note: colorless gas; under normal conditions, does not react with other chemical elements, very rare

Name: Antimony
Symbol: Sb
Atomic Number: 51
Atomic Weight: 121,757 g/mol
Oxidation States: +/-3, 5
Boiling Point: 1860 K
Melting Point: 903,91 K
Density: 6,69 g/cm³
Electron Configuration: [Kr]4d10,5s2,p3
Acid/Base Properties: Acidic
Crystal Structure: Rhombohedral
Electronegativity: 2,05
Heat of Vaporization: 67,97 kJ/mol
Heat of Fusion: 19,83 kJ/mol
Electrical Conductivity: 2,6 10⁶ (Om cm)^-1
Thermal Conductivity: 24,3 W/(m K) (at 300 K)
Specific Heat Capacity: 0,207 J/(g K) (at 300 K)
First Ionization Potential: 8,641
Atomic Volume: 18,40 cm³/mol
Atomic Radius: 1,59 A
Covalent Radius: 1,40 A
Synthetic: No
Discovery: 1600 BC; discoverer unknown
Note: metalloid; shiny and brittle; used in storage batteries and as an additive to harden other metals

Name: Tellurium
Symbol: Te
Atomic Number: 52
Atomic Weight: 127,60 g/mol
Oxidation States: 4, -2,6
Boiling Point: 1261 K
Melting Point: 722,72 K
Density: 6,24 g/cm³
Electron Configuration: [Kr]4d10,5s2,p4
Acid/Base Properties: Acidic
Crystal Structure: Hexagonal
Electronegativity: 2,1
Heat of Vaporization: 50,63 kJ/mol
Heat of Fusion: 17,49 kJ/mol
Electrical Conductivity: 2x10e-4 10⁶ (Om cm)^-1
Thermal Conductivity: 2,35 W/(m K) (at 300 K)
Specific Heat Capacity: 0,202 J/(g K) (at 300 K)
First Ionization Potential: 9,009
Atomic Volume: 20,50 cm³/mol
Atomic Radius: 1,42 A
Covalent Radius: 1,36 A
Synthetic: No
Discovery: 1783; by von Reichenstein in Romania
Note: shiny white metal; burns in air; used in electronics and as an additive to metals to make them easier to form

Name: Iodine
Symbol: I
Atomic Number: 53
Atomic Weight: 126,9045 g/mol
Oxidation States: +/-1, 5,7
Boiling Point: 457,5 K
Melting Point: 386,7 K
Density: 4,93 g/cm³
Electron Configuration: [Kr]4d10,5s2,p5
Acid/Base Properties: Acidic
Crystal Structure: Orthorhombic
Electronegativity: 2,66
Heat of Vaporization: 20,9 kJ/mol
Heat of Fusion: 7,76 kJ/mol
Electrical Conductivity: 10e-11 10⁶ (Om cm)^-1
Thermal Conductivity: 0,449 W/(m K) (at 300 K)
Specific Heat Capacity: 0,145 J/(g K) (at 300 K)
First Ionization Potential: 10,451
Atomic Volume: 25,70 cm³/mol
Atomic Radius: 1,32 A
Covalent Radius: 1,33 A
Synthetic: No
Discovery: 1811; by Courtois in Paris, France
Note: black, shiny non-metal solid; changes state from solid to gas (sublimes) at room temperature; used in dyes and disinfectants

Name: Xenon
Symbol: Xe
Atomic Number: 54
Atomic Weight: 131,29 g/mol
Oxidation States: 0,2,4,6
Boiling Point: 165,1 K
Melting Point: 161,39 K
Density: 5,90 (Gas 273K g/l)
Electron Configuration: [Kr]4d10,5s2,p6
Crystal Structure: Cubic, face centered
Electronegativity: 2,6
Heat of Vaporization: 12,64 kJ/mol
Heat of Fusion: 2,30 kJ/mol
Thermal Conductivity: 0,00569 W/(m K) (at 300 K)
Specific Heat Capacity: 0,158 J/(g K) (at 300 K)
First Ionization Potential: 12,130
Atomic Volume: 42,9 cm³/mol
Atomic Radius: 1,24 A
Covalent Radius: 1,31 A
Synthetic: No
Discovery: 1898; Ramsay ? Travers; London
Note: colorless gas; under normal conditions, does not react with other elements; used in light bulbs and research laboratories

Name: Astatine
Symbol: At
Atomic Number: 85
Atomic Weight: 210 (most stable) g/mol
Oxidation States: +/-1, 3,5,7
Boiling Point: 610 K
Melting Point: 575 K
Electron Configuration: [Xe]4f14,5d10,6s2,p5
Electronegativity: 2,2
Heat of Vaporization: 30 kJ/mol
Heat of Fusion: 12 kJ/mol
Thermal Conductivity: 1,7 W/(m K) (at 300 K)
Atomic Radius: 1,45 A
Covalent Radius: 1,47 A
Synthetic: No
Discovery: 1940; Corson; Berkeley, California
Note: metalloid; soft, gray, and brittle; burns in oxygen; used in glass, insecticides and wood preservatives

Name: Radon
Symbol: Rn
Atomic Number: 86
Atomic Weight: 222 (most stable) g/mol
Oxidation States: 0,2
Boiling Point: 211,4 K
Melting Point: 202 K
Density: 9,73 g/cm³
Electron Configuration: [Xe]4f14,5d10,6s2,p6
Crystal Structure: Cubic, face centered
Heat of Vaporization: 16,40 kJ/mol
Heat of Fusion: 2,9 kJ/mol
Thermal Conductivity: 0,00364 W/(m K) (at 300 K)
Specific Heat Capacity: 0,094 J/(g K) (at 300 K)
First Ionization Potential: 10,748
Atomic Volume: 50,5 cm³/mol
Atomic Radius: 1,34 A
Synthetic: No
Discovery: 1900; by Dorn in Halle, Germany
Note: colorless gas; radioactive; does not react with other chemical elements; very toxic to humans