广东快乐十分开奖结果

Toll free:+86-400 882 8982 中文 ENG

B

Boron is a chemical element with atomic number 5 and the chemical symbol B. Boron is a trivalent nonmetallic element which occurs abundantly in the evaporite ores borax and ulexite. Boron is never found as a free element in nature.

Several allotropes of boron exist; amorphous boron is a brown powder, though crystalline boron is black, hard (9。3 on Mohs' scale), and a weak conductor at room temperature。 Elemental boron is used as a dopant in the semiconductor industry, while boron compounds play important roles as light structural materials, nontoxic insecticides and preservatives, and reagents for chemical synthesis。

Boron is an essential plant nutrient, although higher soil concentrations of boron may also be toxic to plants. As an ultratrace element, boron is necessary for the optimal health of rats and presumably other mammals, though its physiological role in animals is poorly understood.

TECHNICAL DATA
SymbolBDenSity/gcm-3 (β rhombohedral)2.35
Atomic number5(α rhombohedral)2.45
No. of naturally occurring isotopes2Melting point /°C (β rhombohedral)2180
Atomic weight10.81Boiling point /°C (β rhombohedral)~3650
Electronic configuration[He] 2s22p1ΔHsub/kJmol-1570
Ionization energy/kJmol -1800.5Electronegativity χ2
II2426.5Electrical conductivity
III3658.7(25°C)/ohm-1 cm-1l.5x 10-6
EVAPORATION TECHNIQUES
Temperature (oC) @Vap. PressureTechniquesRemarks
10-8 Torr10-6 Torr10-4 TorrElectron BeamCrucibleCoilBoat
1278 Sublimes1548 Sublimes1797 SublimesExcellentGraphite & Vitreous Graphite-GraphiteMaterial explodes with rapid cooling. Forms carbide with container.



B
Sputtering Targets
Matierial SymbolAtomic Number     Thermal Conductivity         Theoretical Density 
W/m.K           g/cc
Boron_BB5272.37



Below is the periodic table of chemical elements。The elements in red are the ones Nexteck's product contain。 Click them, you will come to the details。

24-hour hotline:+86-400 882 8982

logo.png

Providing real-time and high quality service

NEXTECK (CHINA) - SHENZHEN
Tower A1001, Galaxy Century, No 3069, CaiTian Rd, Futian District, Shenzhen, China
Zip Code: 518026
Tel: +86-755-8256-1631
Fax:+86-755-8256-1691
E-mail:nexteck@chinajddz.com
Hotline:+86-400 882 8982

PRODUCTION PLANT
Wenchuan Rd, Alley 5300/1, Baoshan District, Shanghai, China
Zip Code: 200942
Tel: +86-21-3638-0189
Fax: +86-21-3638-0109
E-mail: nexteck@chinajddz.com.cn

福建11选5 陕西快乐十分 云南快乐十分 天津快乐十分走势图 陕西快乐十分走势图 山西快乐十分走势图 秒速赛车平台 天津快乐十分 乐盈彩票APP 湖南快乐十分走势