Hesperium was the name assigned to the element with atomic number

Atomic number

In chemistry and physics, the atomic number is the number of protons found in the nucleus of an atom and therefore identical to the charge number of the nucleus. It is conventionally represented by the symbol Z. The atomic number uniquely identifies a chemical element...

 94, now known as plutonium

Plutonium

Plutonium is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation...

.
It was named in Italian Esperio after a Greek name of Italy, Hesperia, "the land of the West".
The same team assigned the name ausonium

Ausonium

Ausonium was the name assigned to the element with atomic number 93, now known as neptunium. It was named after a Greek name of Italy, Ausonia....

 to element 93, after Ausonia

Ausonia

-Places:Argentina* Ausonia, Argentina, a community in General San Martín Department, CórdobaItaly* Ausonia, Lazio, a comune in the Province of Frosinone-Ships:* German aircraft carrier I , a German aircraft carrier...

, a poetic name of Italy. By comparison, Uranium

Uranium

Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...

 has atomic number 92.

The discovery of the element, now discredited, was claimed by Enrico Fermi

Enrico Fermi

Enrico Fermi was an Italian-born, naturalized American physicist particularly known for his work on the development of the first nuclear reactor, Chicago Pile-1, and for his contributions to the development of quantum theory, nuclear and particle physics, and statistical mechanics...

 and a team of scientists at the University of Rome

University of Rome La Sapienza

The Sapienza University of Rome, officially Sapienza – Università di Roma, formerly known as Università degli studi di Roma "La Sapienza", is a coeducational, autonomous state university in Rome, Italy...

 in 1934. Following the discovery of nuclear fission

Nuclear fission

In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons , and releasing a tremendous amount of energy...

 in 1938, it was realized that Fermi's hesperium was a mixture of barium

Barium

Barium is a chemical element with the symbol Ba and atomic number 56. It is the fifth element in Group 2, a soft silvery metallic alkaline earth metal. Barium is never found in nature in its pure form due to its reactivity with air. Its oxide is historically known as baryta but it reacts with...

, krypton

Krypton

Krypton is a chemical element with the symbol Kr and atomic number 36. It is a member of Group 18 and Period 4 elements. A colorless, odorless, tasteless noble gas, krypton occurs in trace amounts in the atmosphere, is isolated by fractionally distilling liquified air, and is often used with other...

 and other elements. The actual element was discovered several years later, and named plutonium.

Fascist authorities wanted one of the elements to be named littorio after the Roman lictor

Lictor

The lictor was a member of a special class of Roman civil servant, with special tasks of attending and guarding magistrates of the Roman Republic and Empire who held imperium, the right and power to command; essentially, a bodyguard...

es who carried the fasces

Fasces

Fasces are a bundle of wooden sticks with an axe blade emerging from the center, which is an image that traditionally symbolizes summary power and jurisdiction, and/or "strength through unity"...

, a symbol appropriated by Fascism.