B

Boron

IUPAC: Boron

B Elements CAS 7440-42-8
Quick Reference
Formula / NotationB
CAS Number7440-42-8
Molecular Weight10.81
Melting Point2076.0
Boiling Point3927.0
Density2.34
SolubilityInsoluble in water
AppearanceDark brown amorphous powder or black crystalline solid
Also Known AsB, boron element
CategoryElements

What is Boron?

Boron is a metalloid, atomic number 5. Does not occur as free element - found in borax and boric acid. Forms wide range of covalent compounds. B-10 is an excellent neutron absorber.

Formula & Notation

B

IUPAC Name: Boron

Other Names / Synonyms: B, boron element

Properties & Characteristics

Atomic number: 5. Atomic mass: 10.811 g/mol. Period 2, Group 13 (metalloid). Melting point: 2076 C. Boiling point: 3927 C. Density: 2.34 g/cm3. Electronegativity: 2.04. Electron-deficient (3 valence electrons). Isotopes: B-10 (20%), B-11 (80%).

Physical Data

PropertyValue
Melting Point2076.0
Boiling Point3927.0
Density2.34
Molecular Weight10.81
SolubilityInsoluble in water
AppearanceDark brown amorphous powder or black crystalline solid

Uses & Applications

Borosilicate glass (Pyrex). Borax cleaning agent and flux. Boric acid insecticide. Nuclear reactor control rods. P-type semiconductor dopant. Boron carbide (B4C) abrasive. Boron nitride lubricant.

Safety Information

Low acute toxicity as element. Boric acid mildly toxic - avoid ingestion. Fine boron powder: dust explosion risk. Boron trifluoride (BF3) gas: corrosive and toxic.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Boron
Formula B
CAS Number 7440-42-8
Molecular Weight 10.81
Category Elements
Synonyms B, boron element

Frequently Asked Questions

Boron is a metalloid, atomic number 5. Does not occur as free element - found in borax and boric acid. Forms wide range of covalent compounds. B-10 is an excellent neutron absorber.

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