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Information valid for Es-252 unless otherwise noted

Basic Information

Symbol: Es
Atomic Number: 99
Mass: (252.0)
Melting Point: Unknown
Boiling Point: Unknown
Number of Protons/Electrons: 99
Number of Neutrons: 153
Classification: Rare Earth
Crystal Structure: Unknown
Density @ 293 K: Unknown
Color: Unknown

Atomic Structure

[Bohr Model of Einsteinium]
Number of Energy Levels: 7

  1. First Energy Level: 2
    Second Energy Level: 8
    Third Energy Level: 18
    Fourth Energy Level: 32
    Fifth Energy Level: 29
    Sixth Energy Level: 8
    Seventh Energy Level: 2


Isotope Half Life
Es-246 7.7 minutes
Es-248 26.0 minutes
Es-249 1.7 hours
Es-250 8.6 hours
Es-251 1.4 days
Es-252 1.3 years
Es-253 20.5 days
Es-254 276.0 days
Es-254m 1.6 days
Es-255 40.0 days


Date of Discovery: 1952
Discoverer: Argonne, Los Alamos, University of California
Name Origin: After Albert Einstein
Uses: No uses known
Obtained From: Man-made