Boron (symbol B, atomic number 5) is a metalloid essential to borosilicate glass, detergents, and neutron-absorbing control rods. It is classified as a metalloid and sits in group 13, period 2 of the periodic table.
Overview
Boron is the chemical element with atomic number 5 and the symbol B. With a standard atomic weight of 10.81, it is a metalloid. In the periodic table it occupies group 13 and period 2, and under standard conditions it is normally a solid. Boron is a metalloid essential to borosilicate glass, detergents, and neutron-absorbing control rods.
Atomic structure
An atom of Boron has 5 protons in its nucleus and, when neutral, 5 electrons arranged in the configuration [He] 2s2 2p1. Its standard atomic weight of 10.81 reflects the natural mix of its stable isotopes.
Discovery and place in the table
Boron was discovered in 1808 by Joseph Louis Gay-Lussac, Louis Jacques Thénard. It follows Beryllium (Be) and precedes Carbon (C) in order of atomic number.
| Atomic number | 5 |
|---|---|
| Symbol | B |
| Atomic mass | 10.81 |
| Category | Metalloid |
| Group | 13 |
| Period | 2 |
| Electron configuration | [He] 2s2 2p1 |
| Phase at STP | Solid |
| Discovered | 1808 (Joseph Louis Gay-Lussac, Louis Jacques Thénard) |