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Information valid for Sb-122 unless otherwise noted

Basic Information

Symbol: Sb
Atomic Number: 51
Mass: 121.76
Melting Point: 630.0 C
Boiling Point: 1750.0 C
Number of Protons/Electrons: 51
Number of Neutrons: 71
Classification: Metalloid
Crystal Structure: Rhombohedral
Density @ 293 K: 6.684 g/cm3
Color: bluish

Atomic Structure

[Bohr Model of Antimony]
Number of Energy Levels: 5

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


Isotope Half Life
Sb-117 2.8 hours
Sb-119 38.1 hours
Sb-120 15.89 minutes
Sb-121 Stable
Sb-122 2.7 days
Sb-123 Stable
Sb-124 60.2 days
Sb-125 2.75 years
Sb-126 12.4 days
Sb-126m 19.0 minutes
Sb-127 3.84 days
Sb-129 4.4 hours


Date of Discovery: Known to the ancients
Discoverer: Unknown
Name Origin: From the Greek words anti (opposed) and monos (solitude)
Symbol Origin: Greek
Uses: hardens lead, plastics, chemicals
Obtained From: stibnite, valentinite