Berkelium


Introduction

During the synthesis of Americium 243, Seaborg's group synthesized a few milligrams of the element Berkelium. It is a synthetic element found in the periodic table. In 1967 about one gram of Berkelium has been synthesized by the united states. In 2009 about 22 milligrams has been synthesized at Oak Ridge after 250 days of irradiation. It is the fifth synthesized trans uranium element is Berkelium. And it is the eighth member of the actinides. Berkelium metal is not yet obtained in the elemental form. It is synthesized in its compound form such as $\mathrm{BkO_{2}}$, etc.

The symbol used for its representation is 'Bk'. The name Berkelium has been given because the place of discovery is Berkeley. This compound has no practical application and uses as it is a rare element only scientific interest is there.

What is Berkelium?

Berkelium is a soft radioactive metal that has a silver appearance with atomic number 97. It is found in period 7 of the periodic table along with Actinides. The location of this element in the periodic table is right to actinide curium, left to actinide californium, and below terbium, lanthanide. So it is an f block element. And are radioactive metals. But it is a very rare element so its use is also limited to a smaller extent. The existence of this element is in the $\mathrm{Bk^{3+}}$ and $\mathrm{Bk^{4+}}$ states in its solution form. And the solubility property of these elements is just similar to that of its other members commonly like the element Cerium of the Actinide series.

The compounds of this element are $\mathrm{BkO_{2}}$ and $\mathrm{Bk_{2}O_{2}}$ and the trihalides, $\mathrm{BkCl_{3}}$, Berkelium trichloride has been synthesized in a trace amount. This metallic element is easily attacked by air and acids. But are unreactive in alkalis. Along with these compounds, other compounds such as Berkelium oxychloride, $\mathrm{BKOCL}$, Berkelium trioxide, $\mathrm{BkO_{3}}$ , and Berkelium trifluoride, $\mathrm{BkF_{3}}$ are also detected by the X-ray diffraction studies.

Images Coming soon

Discovery

Stanley Thompson, Glenn Seaborg, and Albert Ghiorso in December 1949 first discovered Berkelium at Berkeley. And because of this reason, the element has been given the name Berkelium. The discovery is done by the bombardment of americium- 241 with the Helium nuclei or alpha particles for many hours in a cyclotron of size 60 inches. The new element created was separated using ion-exchange chromatography. Then the obtained element was identified to be berkelium-243. Berkelium trichloride, $\mathrm{BkCl_{3}}$ weighed about three billionth grams is the first compound made with Berkelium and was done in 1962.

Images Coming soon

Occurrence

On earth, Berkelium is found in some places along with other radioactive elements in places that are used in the atmospheric nuclear weapon tests in 1945 and 1980. It is also found in some places that are fond of nuclear disasters such as the 1968 Thule Air Base B-52 crash, the Three Mile Island accident, and the Chornobyl disaster.

Berkelium is purely a synthetic element so its occurrence of them in the Earth's crust is also very rare. And also some amount is found due to human intervention only. Many isotopes of this compound have been found and all are radioactive too, but the thing is that only artificial synthesis is possible for this element. Only a small amount of this element is synthesized so far. This element has been discovered in Przybylski's Star. Berkelium along with some transuranium elements has been found naturally in the natural fission reactor located at Oklo.

Properties of Berkelium

Berkelium is a soft metal that is highly soluble in mineral acids and is oxidized rapidly in presence of oxygen at high temperatures and which leads to the formation of oxides. It shows double hexagonal close-packed and face-centred cubic crystal forms. It also has numerous alloys. Some important properties of this element are tabulated in the following table.

Berkelium Bk
Block f block
Atomic number 97
Electronic configuration $\mathrm{[Rn]5f^{9}7s^{2}}$
Group Actinides
State at 20°C Solid
Atomic radius 2.44°C
Melting point 986°C
Ionization energies (kJ/mol) 598.007(1st)
Key isotopes $\mathrm{Bk^{247},Bk^{249}}$
Oxidation states +4, +3
Density ($\mathrm{gcm^{-3}}$) 14.78
Boiling point Not found
Relative atomic mass 247

Isotopes of Berkelium

There are almost 14 isotopes of Berkelium has been known. And the mass number ranges from 238 to 251. Among the isotopes of Berkelium, the longest-lived one is Berkelium 247. The half-life of Berkelium 247 is about 1380 years. The isotope that is most widely used is Berkelium 249 with a half-life of 330 days only and is because of the production in a weighable amount by the nuclear reaction starting with curium 244. Some of the isotopes and their molecular weight are given in the table.

Isotope Molecular weight
$\mathrm{Bk^{245}}$ 245.066
$\mathrm{Bk^{246}}$ 246.069
$\mathrm{Bk^{247}}$ 247.07
$\mathrm{Bk^{249}}$ 249.075
$\mathrm{Bk^{250}}$ 250.078

Uses of Berkelium

As Berkelium is one of the rare elements the commercial use of this element and its compound is very less. But because of the long half-life and availability in the microgram quantity make it use as an element to synthesize heavier elements by its bombardment. And also this is used in some amount of scientific research. The element tennessine is prepared by using the Berkelium element. It is currently not used for any biological and technical applications.

Conclusion

Berkelium is a soft radioactive metallic element that is rarely found. It is a synthetic element that can be obtained only by some artificial methods. It was discovered by Stanley Thompson, Glenn Seaborg, and Albert Ghiorso in December 1949 by the bombardment of alpha particles with Americium 241. It is a soft metal that has a high solubility in acids and is easily oxidizable.

They are rarely found in Earth's crust so the uses of Berkelium are also less. It is only useful in the synthesis of Tennessee am heavier elements. There are numerous isotopes of this compound. Among them, the most used isotope is Berkelium 247 with a half-life of about 1380 days only.

FAQs

Q1. Is Berkelium toxic?

Ans. Berkelium is a toxic compound as it is a compound that belongs to the group Actinides. Since most of the elements found in the Actinides are radioactive Berkelium is also radioactive.

Q2. What does berkelium decay into?

Ans. The isotope of Berkelium, berkelium-247 undergoes decay to produce the compound americium-243.

Q3. Is Berkelium toxic to the environment?

Ans. About less than a gram of Berkelium element is synthesized annually for scientific research, it doesn't cause any harm to the environment. And also it is a synthetic element the occurrence of it in the Earth's crust is also not found, so it will not affect the environment at all.

Q4. Is Berkelium ductile?

Ans. Berkelium is a shiny silvery metal. So it has all the properties of normal metals. So it is malleable, sonorous, and ductile. It has a high melting point too.

Q5. What is the number of protons and electrons in Berkelium?

Ans. The atomic number of Berkelium is 97, so it contains a total of 97 protons and 97 electrons.

Q6. Can we create new elements?

Ans. New elements can be synthesized using artificial methods such as by the bombardment of other elements with high-energy alpha particles. Which leads to the change in the number of protons present on them.

Updated on: 15-Dec-2022

207 Views

Kickstart Your Career

Get certified by completing the course

Get Started
Advertisements