Rubidium at Chemical Elements.com 


 

Basic Information


Name: Rubidium
Symbol: Rb
Atomic Number: 37
Atomic Mass: 85.4678 amu
Melting Point: 38.89 °C (312.04 °K, 102.002 °F)
Boiling Point: 688.0 °C (961.15 °K, 1270.4 °F)
Number of Protons/Electrons: 37
Number of Neutrons: 48
Classification: Alkali Metal
Crystal Structure: Cubic
Density @ 293 K: 1.532 g/cm3
Color: silver


Atomic Structure

[Bohr Model of Rubidium]  
Number of Energy Levels: 5

    First Energy Level: 2
    Second Energy Level: 8
    Third Energy Level: 18
    Fourth Energy Level: 8
    Fifth Energy Level: 1

Isotopes

Isotope Half Life
Rb-81 4.57 hours
Rb-82 2.25 minutes
Rb-83 86.2 days
Rb-84 32.9 days
Rb-85 Stable
Rb-86 18.65 days
Rb-87 4.8E10 years
Rb-88 17.7 minutes
Rb-89 15.44 minutes
Rb-90 2.6 minutes
Rb-90m 4.3 minutes

Facts


Date of Discovery: 1861
Discoverer: R. Bunsen
Name Origin: From the Latin word rubidus (red)
Uses: catalyst, photocells
Obtained From: lithium production