د ويکيپېډيا، وړیا پوهنغونډ له خوا
Boron, 5Bboron (β-rhombohedral) [۱] |
|
Pronunciation | /ˈbɔərɒn/ |
---|
Allotropes | α-, β-rhombohedral, β-tetragonal (and more) |
---|
Appearance | black-brown |
---|
|
|
|
اټومي شمیره (Z) | 5 |
---|
گروپ, پیریود | group 13 (boron group), period 2 |
---|
بلاک | p-block |
---|
Element category | metalloid |
---|
معياري اټومي وزن (Ar) | - [10.806, 10.821][۲]
- conventional: 10.81
|
---|
Electron configuration | [He] 2s2 2p1 |
---|
Electrons per shell | 2, 3 |
---|
|
حالت (at STP) | جامد |
---|
دويلې کيدو ټکى | 2349 K (2076 °C, 3769 °F) |
---|
يشنا ټکی | 4200 K (3927 °C, 7101 °F) |
---|
Density when liquid, at m.p. | 2.08 g/cm3 |
---|
Heat of fusion | 50.2 kJ/mol |
---|
Heat of vaporization | 508 kJ/mol |
---|
Molar heat capacity | 11.087 J/(mol·K) |
---|
Vapor pressure
P (Pa)
|
1
|
10
|
100
|
1 k
|
10 k
|
100 k
|
at T (K)
|
2348
|
2562
|
2822
|
3141
|
3545
|
4072
| |
|
Oxidation states | 3, 2, 1, −1, −5[۳][۴] (a mildly acidic oxide) |
---|
Electronegativity | Pauling scale: 2.04 |
---|
Ionization energies | - 1st: 800.6 kJ/mol
- 2nd: 2427.1 kJ/mol
- 3rd: 3659.7 kJ/mol
- (more)
|
---|
Atomic radius | empirical: 90 pm |
---|
Covalent radius | 84±3 pm |
---|
Van der Waals radius | 192 pm |
---|
|
Crystal structure | rhombohedral |
---|
Speed of sound thin rod | 16,200 m/s (at 20 °C) |
---|
Thermal expansion | β form: 5–7 µm/(m·K) (at 25 °C)[۵] |
---|
د تودوخې تېرېدنه | 27.4 W/(m·K) |
---|
Electrical resistivity | ~106 Ω·m (at 20 °C) |
---|
Magnetic ordering | diamagnetic[۶] |
---|
Magnetic susceptibility (χmol) | −6.7·10−6 cm3/mol[۷] |
---|
Mohs hardness | ~9.5 |
---|
CAS Number | 7440-42-8 |
---|
|
Discovery | Joseph Louis Gay-Lussac and Louis Jacques Thénard[۸] (30 June 1808) |
---|
First isolation | Humphry Davy[۹] (9 July 1808) |
---|
|
|
10B content may be as low as 19.1% and as high as 20.3% in natural samples. 11B is the remainder in such cases.[۱۱] |
| references | in Wikidata |
بورون (په انگرېزي: Boron) له کیمیاوي عناصرو څخه یو دی چې په تناوبي جدول کې د B سمبول او ۵ اتمي شمېرې په وسیله ښودل شوی دی.
- ↑ Van Setten et al. 2007, pp. 2460–1
- ↑ Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil).
- ↑ Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil).
- ↑ کينډۍ:Cite article
- ↑ Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil).
- ↑ Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil).
- ↑ Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil).
- ↑ Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil).
- ↑ Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil).
- ↑ ۱۰٫۰ ۱۰٫۱ Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil).
- ↑ Lua error in Module:Citation/CS1/Utilities at line 38: bad argument #1 to 'ipairs' (table expected, got nil).
دا ليکنه نابشپړه ده، تاسې ددې ليکنې په بشپړولو کې د ويکيپېډيا سره مرسته کولای شئ.
|