Bor
5
B
Skupina
13
Perioda
2
Blok
p
Protony
Elektrony
Neutrony
5
5
6
Hlavní vlastnosti
Atomové číslo
5
Atomová hmotnost
10,811
Hmotnostní číslo
11
Kategorie
Polokovy
Barva
Černá
Radioaktivní
Ne
Z arabského slova Buraq, persky burah
Krystalografická soustava
Rhomboedrální
Historie
Boron compounds have been known for thousands of years, but the element was not discovered until 1808 by Sir Humphry Davy and by Gay-Lussac and Thenard.
Boron was not recognized as an element until it was isolated in 1808 by Sir Humphry Davy and by Joseph Louis Gay-Lussac and Louis Jacques Thénard.
Jöns Jakob Berzelius identified boron as an element in 1824.
Boron was not recognized as an element until it was isolated in 1808 by Sir Humphry Davy and by Joseph Louis Gay-Lussac and Louis Jacques Thénard.
Jöns Jakob Berzelius identified boron as an element in 1824.
Elektronů v obalu
2, 3
Elektronová konfigurace
[He] 2s2 2p1
Boron is an essential nutrient for all green plants
Fyzické vlastnosti
Skupenství
Pevná
Hustota
2,34 g/cm3
Teplota tání
2349,15 K | 2076 °C | 3768,8 °F
Teplota varu
4200,15 K | 3927 °C | 7100,6 °F
Skupenské teplo tání
50 kJ/mol
Skupenské teplo varu
507 kJ/mol
Měrná tepelná kapacita
1,026 J/g·K
Hojnost v zemské kůře
0,00086%
Hojnost ve vesmíru
1×10-7%
Číslo CAS
7440-42-8
PubChem CID číslo
5462311
Atomové vlastnosti
Atomový poloměr
90 pm
Kovalentní poloměr
84 pm
Elektronegativita
2,04 (Paulingova stupnice)
Ionizační potenciál
8,298 eV
Molární objem
4,6 cm3/mol
Tepelná vodivost
0,274 W/cm·K
Oxidační čísla
1, 2, 3
Aplikace
Boron oxide is used in glassmaking and ceramics.
Borax is used in making fiberglass, as a cleansing fluid, a water softener, insecticide, herbicide and disinfectant.
Boric acid is used as a mild antiseptic and as a flame retardant.
Boron shielding is used as a control for nuclear reactors.
Borax is used in making fiberglass, as a cleansing fluid, a water softener, insecticide, herbicide and disinfectant.
Boric acid is used as a mild antiseptic and as a flame retardant.
Boron shielding is used as a control for nuclear reactors.
Elemental boron, boron oxide, boric acid, borates and many organoboron compounds are non-toxic
Izotopy
Stabilní izotopy
10B, 11BNestabilní izotopy
7B, 8B, 9B, 12B, 13B, 14B, 15B, 16B, 17B, 18B, 19B