Protactinium (also known by its atomic symbol, Pa) is the 91st element on the periodic table. As you can tell by the atomic number, protactinium has 91 protons and 91 electrons. It also has 140 neutrons, and its mass is 213.03587 amu (atomic mass units). Also, Protactinium has a melting point of 2,854 degrees Fahrenheit, but its boiling point is so far unknown. Protactinium was discovered in 1917 by radiochemist Frederick Soddy with help from his partner, John Arnold Cranston, when they figured out how to stabilize it. German scientists claim to have created a stable isotope of protactinium in 1916 but Cranston said he had actually discovered it in 1915, but his notes were locked away while he was on duty in World War I. This chain of events has lead to some debate over the actual discovery dates of the element but it is generally agreed that it was discovered around 1917. …show more content…
The three elements used to discover Protactinium also belong to the Rare Earth Actinides series. Although Soddy and Cranston figured out a way to stabilize it, Protactinium is one of the very few naturally-occurring Rare Earth Actinides and occurs in soil, rock, plants, and surface water. When inhaled in small amounts, Protactinium can cause cancer in the liver and kidneys, but it does not play a huge biological role. Geologically, it does not affect much, and poses no threat to the Department of Energy or to the safety of groundwater. Protactinium, however, is linked to actinium. In fact, it got its name because protos is greek for first, as in first before actinium. Prot actinium. When held in your hand, it looks silvery-white (as most of the family does) and rough. Here is an