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Information valid for At-210 unless otherwise noted

Basic Information

Symbol: At
Atomic Number: 85
Mass: (210.0)
Melting Point: 302.0 C
Boiling Point: 337.0 C
Number of Protons/Electrons: 85
Number of Neutrons: 125
Classification: Halogen
Crystal Structure: Unknown
Density @ 293 K: Unknown
Color: Unknown

Atomic Structure

[Bohr Model of Astatine]
Number of Energy Levels: 6

  1. First Energy Level: 2
    Second Energy Level: 8
    Third Energy Level: 18
    Fourth Energy Level: 32
    Fifth Energy Level: 18
    Sixth Energy Level: 7


Isotope Half Life
At-206 29.4 minutes
At-208 1.6 hours
At-211 7.2 hours
At-215 0.1 milliseconds
At-217 32.0 milliseconds
At-218 1.6 seconds
At-219 50.0 seconds


Date of Discovery: 1940
Discoverer: D.R. Corson
Name Origin: From the Greek word astatos (unstable)
Uses: No uses known
Obtained From: Man-made