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berylliumboroncarbon
 
B
Al  
 
 

General
Name, Symbol, Number Boron, B, 5
Series Metalloids
Group, Period, Block 13 (IIIA), 2, p
DensityFor other meanings of density, see density (disambiguation Density (symbol: rho Greek: rho) is a measure of mass per unit of volume. The higher an object's density, the higher its mass per volume. The average density of an object equals its total mass div, Hardness 2460 kg/m3Kilogram per cubic metre is the SI measure of density and is represented as kg/m³, where kg stands for kilogram and m³ stands for cubic metre. The density of water is about 1000 kg/m³, since a cubic metre of water weighs about a tonne. kg/m³" is sometimes, 9.3
AppearanceFor alternative meanings, see color (disambiguation). visual arts. Color (or colour is a sensation which (in humans) derives from the ability of the fine structure of the eye to distinguish three differently filtered analyses of a view. The perception of Black
Atomic properties
Atomic weightIn reference to a certain isotope of a chemical element, atomic weight (more accurately relative atomic mass though also called simply atomic mass is the mass of one atom of the isotope expressed in units atomic mass unit amu) such that the Carbon-12 isot 10.811 amuThe atomic mass unit amu , unified atomic mass unit u , or dalton Da , is a small unit of mass used to express atomic masses and molecular masses. It is defined to be 1/12 of the mass of one atom of Carbon-12. Accordingly, :1 u 1/N gram 1/(1000 N) kg (whe
Atomic radiusAtomic radius is the distance from the atomic nucleus to the outmost stable electron orbital in a atom that is at equilibrium and is measured in picometers or Angstroms. Atomic radii are called covalent radii (a reference to the types of bonds formed) whe (calc.) 85 (87) pmPicometre ( American spelling: picometer is an SI measure of length that is equal to 10−12 of a metre. Its symbol is pm and it is commonly used in measuring atomic-scale distances. Atom diameters are in the range from ~30 to 600 pm. 1 pm 1 × 10&minu
Covalent radius 82 pm
van der Waals radius no data
Electron configuration [ He]2s22p1
e- 's per energy level 2, 3
Oxidation states ( Oxide) 3 (mildly acidic)
Crystal structure Rhombohedral
Physical properties
State of matter Solid ( nonmagnetic)
Melting point 2349 K (3769 ° F)
Boiling point 4200 K (7101 °F)
Molar volume 4.39 ×10-6 m3/mol
Heat of vaporization 489.7 kJ/mol
Heat of fusion 50.2 kJ/mol
Vapor pressure 0.348 Pa at 2573 K
Speed of sound 16200 m/s at 293.15 K
Miscellaneous
Electronegativity 2.04 ( Pauling scale)
Specific heat capacity 1026 J/(kg*K)
Electrical conductivity 1.0 10-4/(m· ohm)
Thermal conductivity 27.4 W/(m*K)
1st ionization potential 800.6 kJ/mol
2nd ionization potential 2427.1 kJ/mol
3rd ionization potential 3659.7 kJ/mol
4th ionization potential 25025.8 kJ/mol
5th ionization potential 32826.7 kJ/mol
Most stable isotopes
iso NA half-life DM DE M eV DP
10B 19.9% B is stable with 5 neutrons
11B 80.1% B is stable with 6 neutrons
SI units & STP are used except where noted.

Boron is the chemical element in the periodic table that has the symbol B and atomic number 5. A trivalent metalloid element, boron occurs abundantly in the ore borax. There are two allotropes of boron; amorphous boron is a brown powder, but metallic boron is black. The metallic form is hard (9.3 on Mohs' scale) and a bad conductor in room temperatures. It is never found free in nature.





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