The periodic table in chemistry is a tabular arrangement of chemical elements organized on the basis of increasing order of their atomic number. In addition to arrangement on the basis of atomic number, elements in the periodic table are further arranged in groups on the basis of similar chemical properties. Scientists use the periodic table to study the properties of chemicals and design experiments thereon. Hence, the periodic table has proved to be very valuable in developing chemistry.
However, the periodic table has not always looked the way it does now. Over time, it has undergone many developments wherein many new elements have been added. So, can we add more elements to the periodic table? And when will we reach the end of the periodic table? How many seats are left at the table? In this blog, we’ll answer all these questions.
Let’s begin by briefly examining the periodic table’s history and development.
The Periodic Table: Historical Developments
The extended periodic table used today is the updated version of the periodic table presented by Russian chemist Dmitri Mendeleev in the mid-19th century. However, he wasn’t the first to devise a system to categorize the elements based on specific common properties. There were many who had done it before, but the periodic table by Mendeleev stood out. Scerri, a chemist says, “his (Mendeleev) version is the one that had the biggest impact on the scientific community.”
Let’s look at the history of the periodic table over the years:
- First version – Doberiener’s Triads: The German chemist – Johann Wolfgang Döbereiner, in the early 19th century, made some interesting observations about how matter behaved. He noticed that sets of three-element groupings called triads have similar chemical and physical characteristics. Every group had a center element whose atomic weight was half the atomic weight of the other two elements. The middle element’s properties were also located midway between the two elements. However, this law could not be applied for all elements.
- Second version – Law of Octaves: The English chemist John Alexander Newlands introduced the law of octaves in 1865. He categorized the atoms according to their atomic weights. He claimed that his arrangement represented the octaves of music because every eighth piece in a row shared characteristics in common with the first element in the same row. This law was rejected as it applied only to elements up to Calcium.
- Periodic table by Mendeleev: In 1869, Mendeleev gave a law that stated, “The properties of an element are the periodic function of their atomic masses.” He created the framework that gave rise to the modern periodic table which we use today. In 1870, Lothar Meyer created a periodic table resembling Mendeleev’s and left gaps for undiscovered elements but never predicted their properties. These gaps are still being filled. Today, the extended periodic table has 118 known elements, completing the first seven rows of the table.
New Elements In Periodic Table
At 150 years old, the table is still growing. In 2011, there was an update to include Flerovium (114) and Livermorium (116) and in 2016, four new elements on the periodic table were added including, Nihonium (Nh), Moscovium (Mc), Tennessine (Ts), and Oganesson (Og) with atomic numbers 113, 115, 117, and 118, respectively.
Where did these new elements on the periodic table come from?
The periodic table was gradually filled up till Uranium (element 92), after which synthetic elements were added to the periodic table in 2016. These synthetic elements are highly unstable and classified as super heavy metals. Unlike other elements, superheavy metals do not occur in nature and are created only in laboratories. They are also more radioactive and unstable. To create these elements, scientists use particle accelerators to make charged ions of one element collide with ions of another. This results in the creation of a new element.
So, why not create more?
If the scientists know how to create new elements and have already done it so many times, why not keep doing it? Unfortunately, it doesn’t work that way. The laws of physics don’t bend for us as and when we want. The elements tend to become more unstable at higher atomic numbers.
We previously discussed superheavy elements. Notably, elements with over 104 protons are classified as “superheavy.” They are part of a vast, unknown land that scientists are trying to uncover. They are often very unstable and decay spontaneously as soon as they are formed. This decay might be so quick that it leaves no time to attract and capture an electron to form an atom.
Researchers’ quest hasn’t stopped because of such hurdles and uncertainties. But, the search for new elements is definitely getting more challenging over time. Attempts to synthesize elements past 118 are constantly on but with no success. The creation of elements beyond atomic number 118 looks purely hypothetical for now.
So, Is This The End Of The Periodic Table?
Although the seventh period of the periodic table is now complete, the table in itself may not be fully complete yet. Some scientists still believe that there are a lot of elements to discover and create in the future before we reach the end of the periodic table. The periodic table of elements might have a whole new row added to it someday.
Island Of Stability – A New Hope?
Physicist Richard Feynman predicted the end of the periodic table at element 137. According to his calculations, electrons in elements with an atomic number greater than 137 would need to travel faster than the speed of light to avoid crashing into the nucleus. This would violate the rules of relativity.
However, despite Feynman’s predictions, scientists are eager to keep filling out the periodic table. One big reason is the hope of reaching the conjectured “island of stability.”
The island of stability is a hypothesized group of superheavy elements that do not decay and are more stable than the currently lab-synthesized elements. Reaching the island of stability requires scientists to take advantage of the neutrons and protons. More neutrons can help promote stability, which might make it possible to increase the lifetime of the nucleus. We are not yet at the center of the island of stability because we are neutron-deficient.
One thing is sure: Making new elements will become more challenging due to difficulties in detecting short-lived atoms. Additionally, forging new elements relies on bombarding radioactive atom beams, which is technically challenging and prohibitively expensive.
Final Thoughts on End of The Periodic Table
Scientists have come a long way since the inception of the periodic table. Many new elements have been discovered and added but the quest for adding more elements continues.
Would the ‘island of stability’ of the periodic table be achieved? Or would Richard Feynman’s prediction of element 137 being the end of the periodic table come true? Only time can tell us what the future holds.
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- How many elements are there in the periodic table in chemistry in 2023?
In 2016, four new elements were discovered and added to the periodic table, namely Nihonium (Nh), Moscovium (Mc), Tennessine (Ts), and Oganesson (Og). As a result, there are now 118 elements in the extended periodic table.
- How close are we to making element 119?
The quest to create element 119, the next superheavy element, began at the RIKEN laboratory in Wako, Japan, in December 2017. The Joint Institute for Nuclear Research (JINR) in Dubna also plans to make element 119 at its Superheavy Element Factory (SHEF). SHEF is a facility dedicated to synthesizing and studying superheavy elements at JINR. It recently published the results of some of its experiments.