Name Arsenic
Symbol As
Atomic Number 33
Atomic Mass 74.9216 atomic mass units
Number of Protons 33
Number of Neutrons 42
Number of Electrons 33
Melting Point 817.0 C
Boiling Point 613.0 C
Density 5.72 grams per cubic centimeter
Normal Phase Solid
Family Metalloids
Period 4
Cost Unavailable



Origin of Name From the Greek word "arsenikos" and the Latin word "arsenicum," meaning yellow orpiment
Date and Place of Discovery It's been used since ancient times, but the first recorded use was in 1250 when Albert the Great, an alchemist, heated a compound containing arsenic.
Discovered by Albert the Great aka Albertus Magnus
Common Compounds
Interesting facts
  • It and all its compounds are poisonous.
  • It can contaminate ground water which is what occurred in Bangladesh (see articles).
Common Uses
  • Poisons, such as insecticides
  • Electrical conduits
  • Semiconductors
  • Bronzing


Photo Courtesy of
Chemical Elements
Jefferson Lab
Web Elements

Arsenic Atomic Structure Elements by Name Elements by Number Home