Atomic Properties of B
- Atomic Number of B
- 5
- Atomic Mass of B
- 10.8100 u
- Electron Configuration
- [He] 2s2 2p1
- Electronegativity
- 2.04
- Block
- p-block
- Group
- 13
- Period
- 2
Boron (B) is element 5 on the periodic table. Atomic mass of B: 10.8100 u. B is in period 2, group 13. Melting point of B: 2349.00 K.Density of B: 2.34 g/cm³.
Boron in everyday life and industry
Boron is essential for plants - required for cell wall formation Humans need trace amounts of boron for bone health Boric acid has antiseptic and antifungal properties Boron deficiency in plants causes hollow stems and poor fruit development
Discovered by Sir H. Davy, J.L. Gay-Lussac, L.J. Thénard in England/France, 1808
Name origin: From Arabic and Persian words for borax.
An element of group 13 of the periodic table. There are two allotropes, 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. Boron-10 is used in nuclear reactor control rods and shields. It was discovered in 1808 by Sir Humphry Davy and by J.L. Gay-Lussac and L.J. Thenard.
Boron exists in 2 different structural forms (allotropes), each with unique properties.
Brown powder form, less pure, used industrially
Black, metallic appearance with extreme hardness
Boron has 2 naturally occurring isotopes.
| Isotope | Atomic Mass (u) | Abundance | Half-Life | Decay Mode |
|---|---|---|---|---|
| 105B (B-10)Boron-10 isotope | 10.01293695 | 19.90% | — | — |
| 115B (B-11)Boron-11 isotope | 11.00930536 | 80.10% | — | — |
Data source: NIH PubChem (aggregated from IUPAC, NIST)
Isotopes of Boron have important real-world applications in science and industry.
The large value of the absorption cross section of 10B for thermal neutrons makes this isotope useful for counting neutrons. 10B is being studied as a potential replacement for 3He in radiation detectors [32], [53], [54]. The large thermal absorption cross section of 10B makes the isotope useful in control rods (Fig. IUPAC.5.2) [55].
10B has a high thermal neutron absorption cross section and can readily absorb neutrons via the reaction 10B+n→ 7Li+α. The alpha particles resulting from this reaction carry away a relatively large kinetic energy and are useful for the treatment of malignant tumors in cancer patients [56], [57], [58].
Used with titanium & tungsten to make heat resistant alloys for jets & rockets.
Obtained from kernite, a kind of borax (Na2B4O7·10H2O). High purity boron is produced by electrolysis of molten potassium fluroborate and potassium chloride (KCl).
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