Astatine at Chemical Elements.com 


 

Basic Information


Name: Astatine
Symbol: At
Atomic Number: 85
Atomic Mass: (210.0) amu
Melting Point: 302.0 °C (575.15 °K, 575.6 °F)
Boiling Point: 337.0 °C (610.15 °K, 638.6 °F)
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

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

Isotopes

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

Facts


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