Name       : Protactinium
Symbol     : Pa
Atomic #   : 91
Atom weight: 231
Melting P. : 1600
Boiling P. : 
Oxidation  : +4, +5
Pronounced : PRO-tak-TIN-eh-em
From       : Greek proto+actinium, "parent of actinium"
Identified : Kasimir Fajans and O.H. Gohring in 1913
Appearance : Silvery-white, radioactive metal
Note       : Former known as brevium and protoactinium
             
[Properties]

  Protactinium is a heavy, silvery-white and shiny metal. It oxidizes very
slowly in air. The metal, as well as all of its compounds, is radioactive
and poisonous.
  Protactinium follows thorium in the actinide series of elements. The
actinides are all metals; the series begins with actinium (Ac, element 89)
and ends with lawrencium (Lr, element 103).