Periodic Table

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1HHydrogen 2HeHelium 3LiLithium 4BeBeryllium 5BBoron 6CCarbon 7NNitrogen 8OOxygen 9FFluorine 10NeNeon 11NaSodium 12MgMagnesium 13AlAluminum 14SiSilicon 15PPhosphorus 16SSulfur 17ClChlorine 18ArArgon 19KPotassium 20CaCalcium 21ScScandium 22TiTitanium 23VVanadium 24CrChromium 25MnManganese 26FeIron 27CoCobalt 28NiNickel 29CuCopper 30ZnZinc 31GaGallium 32GeGermanium 33AsArsenic 34SeSelenium 35BrBromine 36KrKrypton 37RbRubidium 38SrStrontium 39YYttrium 40ZrZirconium 41NbNiobium 42MoMolybdenum 43TcTechnetium 44RuRuthenium 45RhRhodium 46PdPalladium 47AgSilver 48CdCadmium 49InIndium 50SnTin 51SbAntimony 52TeTellurium 53IIodine 54XeXenon 55CsCesium 56BaBarium 57LaLanthanum 58CeCerium 59PrPraseodymium 60NdNeodymium 61PmPromethium 62SmSamarium 63EuEuropium 64GdGadolinium 65TbTerbium 66DyDysprosium 67HoHolmium 68ErErbium 69TmThulium 70YbYtterbium 71LuLutetium 72HfHafnium 73TaTantalum 74WTungsten 75ReRhenium 76OsOsmium 77IrIridium 78PtPlatinum 79AuGold 80HgMercury 81TlThallium 82PbLead 83BiBismuth 84PoPolonium 85AtAstatine 86RnRadon 87FrFrancium 88RaRadium 89AcActinium 90ThThorium 91PaProtactinium 92UUranium 93NpNeptunium 94PuPlutonium 95AmAmericium 96CmCurium 97BkBerkelium 98CfCalifornium 99EsEinsteinium 100FmFermium 101MdMendelevium 102NoNobelium 103LrLawrencium 104RfRutherfordium 105DbDubnium 106SgSeaborgium 107BhBohrium 108HsHassium 109MtMeitnerium 110DsDarmstadtium 111RgRoentgenium 112CnCopernicium 113NhNihonium 114FlFlerovium 115McMoscovium 116LvLivermorium 117TsTennessine 118OgOganesson

Boron

5Metalloid

mass 10.810 · solid · group 13 · period 2

Alkali metal6

Alkaline earth metal6

Transition metal38

Post-transition metal11

Metalloid7

Nonmetal7

Halogen6

Noble gas7

Lanthanide15

Actinide15

4Be

Atomic number 5

Boron

Metalloid

In the real world

Dark brown-black boron powder beside hard dark gray boron lumps on white paper. — What it looks likeBoron is a dark brown-black metalloid: a brittle powder or hard crystals, not a shiny metal.

Thick-walled clear borosilicate glass beakers and a flask on a bench. — Where you'd see itBoron makes borosilicate glass that resists heat and sudden temperature changes.

Quick facts

Atomic mass: 10.810
Group: 13
Period: 2
State (STP): solid
Electronegativity: 2.04
Common ox. states: +3

Properties

Electron configuration

[He] 2s² 2p¹

Ionization energy: 800.6 kJ/mol
Electron affinity: 26.7 kJ/mol
Melting point: 2349.00 K (2075.8 °C)
Boiling point: 4200.00 K (3926.8 °C)

How dangerous is it?

0/5 · Safe to handle

As the dark, hard, ordinary solid it is low hazard and safe to handle. Boron is happy to just sit there.

How it bonds

Boron has three valence electrons and forms three covalent bonds - but unlike carbon, it stops there. BF₃ is famous for having only 6 electrons around boron (an "incomplete octet"), which makes it a Lewis acid: it eagerly grabs a lone pair from another molecule (like NH₃) to complete its octet.

Where you meet it

Build Boron trifluorideBF₃
Periodic Quest challengeunlock card

Compounds featuring this element

Boron trifluorideBF₃

Deeper

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