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Information valid for Xe-131 unless otherwise noted

Basic Information

Symbol: Xe
Atomic Number: 54
Mass: 131.29
Melting Point: -111.9 C
Boiling Point: -108.1 C
Number of Protons/Electrons: 54
Number of Neutrons: 77
Classification: Noble Gas
Crystal Structure: Cubic
Density @ 293 K: 5.8971 g/cm3
Color: Colorless Gas

Atomic Structure

[Bohr Model of Xenon]
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: 8


Isotope Half Life
Xe-122 20.1 hours
Xe-123 2.0 hours
Xe-124 Stable
Xe-125 17.1 hours
Xe-126 Stable
Xe-127 36.41 days
Xe-128 Stable
Xe-129 Stable
Xe-129m 8.89 days
Xe-130 Stable
Xe-131 Stable
Xe-131m 4.9 days
Xe-132 Stable
Xe-133 5.24 days
Xe-133m 2.19 days
Xe-134 Stable
Xe-135 9.1 hours
Xe-135m 15.36 minutes
Xe-136 Stable
Xe-137 3.82 minutes
Xe-138 14.13 minutes


Date of Discovery: 1898
Discoverer: Sir William Ramsay
Name Origin: From the Greek word xenon (stranger)
Uses: powerful lamps, bubble chambers
Obtained From: liquid air