Einsteinium

When talk goes around about elements, like oxygen, gold, or iron, the most common thing that comes to mind is that all these elements are naturally occurring. However, not all the elements come on Earth naturally — some are created in the heart of nuclear reactions, under controlled, extreme conditions. One such element is Einsteinium, a rare element in the periodic table that doesn’t occur naturally on Earth. Here, we will be exploring different aspects of this fascinating synthetic element. 

1.0Discovery & Naming of Einsteinium

Einsteinium was first discovered as a result of the fiery aftermath of the Cold War from the debris of the first hydrogen bomb test, with the code name “Ivy Mike”. It was discovered by a team of scientists led by Albert Ghiorso at the University of California, Berkeley, in 1952. 

The test took place in the Pacific Ocean, as a result of which tiny particles of coral and other materials from the ocean blasted into the atmosphere as a big mushroom cloud. These blasted particles were collected and analysed using alpha-particle spectroscopy to discover a new element, later known as Einsteinium. 

The element was named in honour of one of the most famous physicists of his time, Albert Einstein, specifically for his astounding contribution towards theoretical physics and for indirectly giving insights into the concepts of atomic energy. 

2.0Einsteinium in the Periodic Table 

Einsteinium is placed in the actinide series of the periodic table due to its complex electronic configurations and radioactive properties. The actinide series is a group of 15 metallic elements starting from actinium to lawrencium. Being a f-block element, Einsteinium belongs to the seventh period and third group of the periodic table, placed exactly between californium (98) and fermium (100). 

3.0Einsteinium Atomic Number and Atomic Mass 

The atomic number of any element defines its position on the periodic table, along with the number of protons and electrons present in its nucleus and outer shells. Einsteinium’s atomic number is 99, meaning the number of protons and electrons in the element is 99. 

Atomic mass refers to the number of protons and neutrons present in the nucleus of an atom. Einsteinium atomic mass differs based on the isotope, but the most commonly used is einsteinium-253, with an atomic mass of around 252 atomic mass units (u). There are other isotopes of the element, like Es-254 and Es-252, with slightly varying masses and half-lives.

4.0Einsteinium Electronic Configuration 

Atoms of an element lose or gain electrons to become ions in what are referred to as oxidation states. Most elements have common oxidation states where they usually form the stable electronic configuration of their compounds. In the case of einsteinium (Es), the +3 oxidation state is the most stable and commonly seen, particularly in its chemical compounds. Einsteinium's Electronic Configuration for its ground state can be expressed as:

$Rn5f^{11}7s^2$

According to the above electronic configuration of Einsteinium, it can be said that the element has: 

• 2 electrons in the 7s orbital
• 11 electrons in the 5f orbital

Here, Rn refers to the inner electronic configuration of Einsteinium, which is equal to the configuration of the noble gas, radon (Rn). 

5.0Physical Properties of Einsteinium 

Owing to its extreme radioactivity, determining the Physical Properties of Einsteinium has been a challenge for scientists. Moreover, the element is present in a very small amount, in micrograms, which makes it even harder to determine these properties. However, here are some important estimated values and observations regarding its properties: 

• It is solid at room temperature. 
• It is predicted to have a silvery or metallic colour. 
• The melting point of the element is 1133K or 860℃, approximately. 
• The boiling point is approximately 1269K or 996℃. 
• It has an estimated density of 8.84 g/cm³. 
• It possesses a face-centred cubic crystal structure under normal ambient conditions. 

6.0Chemical Properties of Einsteinium 

The Chemical Properties of Einsteinium typically follow the properties of other actinide elements, especially those which are present in the last of the series, such as: 

• Like any other actinide, it has an oxidation state of +3 to form a compound, such as einsteinium oxide (Es₂O₃) and einsteinium chloride (EsCl₃).
• Einsteinium reacts with oxygen, halogens and acids, which are monitored under controlled conditions. 
• Its property of forming complex bonds with organic and inorganic ligands helps scientists study its bonding behaviour. 
• The compounds of Einsteinium are commonly soluble in acids and are good reactants with water. 

7.0Einsteinium and Radioactivity 

As mentioned earlier, Einsteinium is a highly reactive metal which decays very quickly. All the isotopes of the element are unstable, with the most stable one being Einsteinium-252, which has a half-life of about 471 days. Other isotopes, such as einsteinium-253, have a shorter half-life, making it hard to study them extensively. 

The radioactivity of this element is such that it can intensively damage biological tissues, ultimately making it hazardous to health. Therefore, the element is kept with extreme caution with remote handling tools and a shielded environment. Also, the element continuously emits heat that interferes with its own structure and chemical behaviour. 

8.0Uses of Einsteinium 

Although Einsteinium doesn’t have any commercial use due to its limited availability, it does have great importance in various scientific research, including: 

• Synthesisation of another man-made element, Mendelvium (101), by bombarding Einsteinium with alpha particles. 
• Study of the chemistry of the actinide series and nuclear decay processes. 
• Giving an insight into what properties the superheavy elements possess.  
• Understanding the behaviour of elements at the end of the periodic table.