Potassium at Chemical Elements.com 

 

Basic Information


Name: Potassium
Symbol: K
Atomic Number: 19
Atomic Mass: 39.0983 amu
Melting Point: 63.65 °C (336.8 °K, 146.57 °F)
Boiling Point: 774.0 °C (1047.15 °K, 1425.2 °F)
Number of Protons/Electrons: 19
Number of Neutrons: 20
Classification: Alkali Metal
Crystal Structure: Cubic
Density @ 293 K: 0.862 g/cm3
Color: silvery


Atomic Structure

[Bohr Model of Potassium]  
Number of Energy Levels: 4

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

Isotopes

Isotope Half Life
K-39 Stable
K-40 1.28E9 years
K-41 Stable
K-42 12.4 hours
K-43 22.3 hours

Facts


Date of Discovery: 1807
Discoverer: Sir Humphrey Davy
Name Origin: potash
Symbol Origin: From the Latin word kalium
Uses: glass, soap
Obtained From: minerals (carnallite)