5 B Boron 10.81 u

Boron

周期
2
族
13
ブロック
p-ブロック
相 (STP)
Solid

Boron is a metalloid essential for plant growth and used in glass and ceramics. Its compounds, such as borax, have been used for thousands of years.

外観: 黒褐色

About Boron

A metalloid straddling the boundary between metals and nonmetals, boron carries atomic number 5 and an atomic mass of 10.81. In elemental form it appears black-brown and is hard and refractory, melting near 2349 K. Three valence electrons ([He] 2s2 2p1) and an electronegativity of 2.04 favor covalent bonding, and its first ionization energy is 800.6 kJ/mol. Joseph Louis Gay-Lussac helped isolate the element in 1808, though boron compounds such as borax had already been used for thousands of years. Boron is essential to plant growth and is incorporated into glass and ceramics. It belongs to group 13, period 2.

物理的特性

原子質量 10.81 u
密度 2.34 g/cm³
融点 2075.8 °C
沸点 3926.8 °C
STPにおける相 Solid
原子半径 87.0 pm

電子的特性

電気陰性度 2.04
イオン化エネルギー 800.6 eV
電子親和力 26.7 eV
価電子 3

電子配置

配置 [He] 2s² 2p¹

Electron Shell Configuration

Boron electron shell configuration B 2e⁻ 3e⁻
Electron shell structure of Boron — electrons per shell.
Shell Electrons
1 (K) 2
2 (L) 3

Position in Periodic Table

Boron position in the periodic table B

発見

発見者: Joseph Louis Gay-Lussac
年: 1808

ブロックと周期

ブロック

s p d f

周期

1 2 3 4 5 6 7

周期表

ランタノイド アクチノイド

B を含む反応

Boron Trifluoride and Ammonia (Lewis Acid-Base)

BF₃ + NH₃ → BF₃·NH₃

Acid-Base

Positron Emission of Carbon-11

¹¹C → ¹¹B + e⁺ + νₑ

Nuclear

Compounds Containing Boron

Boron Trifluoride

BF₃

Boron Trichloride

BCl₃

Sodium Tetraborate

Na₂B₄O₇

Sodium Borohydride

NaBH₄

Sodium Perborate

NaBO₃

Boric Acid

H₃BO₃

Boron Nitride

BN

Boron Trioxide

B₂O₃

Diborane

B₂H₆

Sodium Borohydride in NaOH

NaBH₄/NaOH

半金属 をもっと見る

14 Si Silicon 32 Ge Germanium 33 As Arsenic 51 Sb Antimony 52 Te Tellurium

Frequently Asked Questions

What is Boron?
Boron (B) is a chemical element with atomic number 5. It is a solid at standard temperature and pressure, classified as a 半金属.
What are the key properties of Boron?
Boron has an atomic mass of 10.81 u, density of 2.34 g/cm³, melting point of 2075.8°C, boiling point of 3926.8°C.
What is the electron configuration of Boron?
The electron configuration of Boron is [He] 2s2 2p1. It is in the p-block of the periodic table.
Who discovered Boron?
Boron was discovered by Joseph Louis Gay-Lussac in 1808.
What is the electronegativity of Boron?
Boron has an electronegativity of 2.04 on the Pauling scale.