Element 5
Boron
Metalloids
Boron (B) is in the p-block of the periodic table — group 13, period 2.
Boron is a metalloid chemical element with symbol B and atomic number 5.
Key data
- Atomic number
- 5
- Atomic mass
- 10.810 u
- Group / Period
- 13 / 2
- Block
- p-block
- Phase at STP
- Solid
- Density
- 2.08 g/cm³
- Melting point
- 2075.8 °C
- Boiling point
- 3926.8 °C
- Electron configuration
- [He] 2s2 2p1
Periodic table block
Boron is in the p-block (group 13, period 2). Elements land in the p-block when their highest-energy electrons fill a p subshell — this region holds most nonmetals, the metalloids, and the metals on the right of the table.
New to this? Periodic table blocks explained: s, p, d, and f
Common uses
- •Pyrex glass
- •Detergents (borax)
- •Semiconductor doping
Discovery
Year: 1808
Discovered by: Joseph Louis Gay-Lussac
Frequently asked questions
What is the atomic number of Boron?
Boron has atomic number 5. Its symbol is B and its atomic mass is 10.81 u.
What category of element is Boron?
Boron is classified as metalloids. It sits in group 13, period 2 of the periodic table.
What block of the periodic table is Boron in?
Boron is in the p-block (group 13, period 2). Its highest-energy electrons occupy the p subshell — you can see this in its electron configuration, [He] 2s2 2p1.
What is Boron used for?
Common uses of Boron include: Pyrex glass, Detergents (borax), Semiconductor doping.
When was Boron discovered?
Boron was discovered in 1808 by Joseph Louis Gay-Lussac.
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