Radium at Chemical Elements.com 

 

Basic Information


Name: Radium
Symbol: Ra
Atomic Number: 88
Atomic Mass: (226.0) amu
Melting Point: 700.0 °C (973.15 °K, 1292.0 °F)
Boiling Point: 1737.0 °C (2010.15 °K, 3158.6 °F)
Number of Protons/Electrons: 88
Number of Neutrons: 138
Classification: Alkaline Earth
Crystal Structure: Cubic
Density @ 293 K: 5.0 g/cm3
Color: silverish


Atomic Structure

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

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

Isotopes

Isotope Half Life
Ra-222 38.0 seconds
Ra-223 11.43 days
Ra-224 3.66 days
Ra-225 14.9 days
Ra-226 1600.0 years
Ra-228 5.76 years

Facts


Date of Discovery: 1898
Discoverer: Pierre and Marie Curie
Name Origin: From the Latin word radius (ray)
Uses: treating cancer
Obtained From: uranium ores