Atomica
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4. Beryllium6. Carbon
5B10.81

Boron

Metalloids

In-between elements with some metal and some non-metal properties. Many are semiconductors.

[He] 2s² 2p¹

Atomic number
5
Atomic mass
10.81
Protons
5
Neutrons
6 (most common)
Electrons
5
Shells
2, 3
State at 25 °C
Solid
Position
Group 13, period 2
Proton (+)Neutron (0)Electron (−)
Discovered byJoseph Gay-Lussac, Louis Thénard and Humphry Davy, 1808Humphry Davy: 7 elementsJoseph Gay-Lussac and Louis Thénard: 1 element

Two French chemists and an English chemist isolated boron in the same year, working separately.

Did you know?

  • Plants need small amounts of boron to grow.
  • It is a metalloid: part metal, part non-metal.

Where it's found

  • Borax
  • Minerals in dry lake beds

What it's used for

  • Heat-proof lab and kitchen glass
  • Fibreglass
  • Cleaning products

Try it

Stretchy slimeAdult helps
  1. 1An adult mixes a little borax powder into warm water.
  2. 2Stir some of this solution into PVA glue.
  3. 3Knead, then wash your hands.

What you'll see: The glue turns into stretchy slime as the borax links the glue molecules together.