boron [B]

Introduction

From the Arabic buraq, borax, its most important ore Pure form isolated in 1808 by British chemist Sir Humphrey Davy & independently by French chemists Joseph-Luis-Gay-Lussac & Louis-Jacques Thenard

Occurrence

• makes up 0.0003% of the earth's crust
• never found its pure form in nature
• occurs as orthoboric acid in certain volcanic spring waters
• occurs in ores
  • rasorite (kernite)
  • borax (tincal)

Characteristics

• trivalent metalloid element
• brown-black solid
• crystalline boron is chemically inert

Uses

• metallurgy & nucleonics
• to make borosilicate glass or Pyrex
• in fission-reactor control rods to capture neutrons & regulate power produced
• used with silicon in making p-type semiconductors
• as an eye disinfectant
• in pyrotechnics to make a green color

Pathology

(Toxicology)

• excessive amounts are poisonous
• once used in medicines

Laboratory

• boron in specimen
  • boron in hair
  • boron in erythrocytes
  • boron in tissue
  • boron in body fluid
    • boron in blood
    • boron in serum/plasma
    • boron in urine

Notes

• essential micronutrient for plants
• foods rich in boron may provide protective effect against prostate cancer
  • red wine
  • almonds
  • coffee
  • certain fruits & nuts

More general terms

• trace element

Additional terms

• borate