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Information valid for As-75 unless otherwise noted

Basic Information

Symbol: As
Atomic Number: 33
Mass: 74.9216
Melting Point: 817.0 C
Boiling Point: 613.0 C
Number of Protons/Electrons: 33
Number of Neutrons: 42
Classification: Metalloid
Crystal Structure: Rhombohedral
Density @ 293 K: 5.72 g/cm3
Color: Gray

Atomic Structure

[Bohr Model of Arsenic]
Number of Energy Levels: 4

  1. First Energy Level: 2
    Second Energy Level: 8
    Third Energy Level: 18
    Fourth Energy Level: 5


Isotope Half Life
As-71 2.7 days
As-72 26.0 hours
As-73 80.3 days
As-74 17.8 days
As-75 Stable
As-76 26.3 hours
As-77 39.0 hours
As-79 9.0 minutes


Date of Discovery: Known to the ancients
Discoverer: Unknown
Name Origin: From the Greek word arsenikos and the Latin word arsenicum
Uses: Poison, conducts electricity, semiconductors
Obtained From: mispickel