Table of Contents (click to expand)
- Dmitri Mendeleev – Father Of The Periodic Table
- Reading The Periodic Table
- Other Interferences
The periodic table is arranged by atomic number, which is the number of protons in an element’s nucleus. The elements are arranged in order of increasing atomic number. The periodic table is also arranged by groups and periods. The elements in a group have the same number of electrons in their outermost orbital. The elements in a period have the same number of electron shells.
The arrangement of the periodic table wasformulatedin order to give a very informative representation of the chemical elements. Each of these elements is specifically placed in the periodic table, keeping specific parameters in mind.
The arrangement of the periodic table has changed over time since its inception. This is because new elements have either been discovered or made by man, andlater added to the periodic table.
Before we dive into the intricacies of the periodic table, let’s first take a walk down memory lane.
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Dmitri Mendeleev – Father Of The Periodic Table
Dmitri Mendeleev, a Russian chemist and inventor, is considered the “father” of the periodic table, according to the Royal Society of Chemistry. During the 1860s, Mendeleev was a popular lecturerat St. Petersburg University in Russia. During this time, there were no authoritative modern organic textbooks that could be used as staple reading material.For this reason, Mendeleev decided to write one and tackle two primary issues: the first being toorganize thedisparate natures of the elements and the secondbeing to solve the dilemma of an authoritative book.
However, this wasn’t as straightforward as onemight imagine in the time of Mendeleev, as there were numerous obstacles to overcome. At that time, less than half the current elements were known, and some of those elements that were present had the wrong data. We could try understanding what Mendeleev went through by giving the analogy of a tough jigsaw puzzle with half the pieces bent out of shape.
Mendeleev ultimately succeeded in his endeavor and wrote the definitive chemistry book of his time, titled “Principles of Chemistry”, which was made into two volumes. While working on the periodic table, he ended up making the most significant contribution to organic chemistry in history. He accomplished this by writing down the properties of each element on a card in an ordered fashion of increasing atomic weight, according to the Royal Society of Chemistry. By doing this, he noticed a particular pattern occurring in the elements.
After intensely trying to work through the pattern for three days, he said that—in a dream—he saw all the elements fall into the right place. He immediately woke up and wrote it down on a piece of paper and went back to sleep. Upon waking, he found that it only needed one correction! Mendeleev arranged the elements both in terms of their atomic weights and valence. He was also smart enough to leave space for new elements that he thought would be discovered (and he was right!). He also predicted the properties of five unknown elements and what their compounds would be, even before their discovery, based on the principles of the periodic table he had arranged.
Also Read: Can We Add New Elements To The Periodic Table?
Reading The Periodic Table
Now, the periodic table can be read in any number of ways, providing a great deal of information about a particular element or group of elements.
Atomic Number
The first and most crucial aspect one can infer from the periodic table is an element’satomic number. The number of protons in an atom is referred to as the atomic number of the element. It also gives a clear indication of the chemical behavior of the element. For example, we can say that carbon atoms have six protons, hydrogen atoms have one and oxygen has eight.
Atomic Symbol
The next crucial aspect is the Atomic Symbol. As mundane as this sounds, the atomic symbol gives us an abbreviation of every element. These symbols are accepted internationally and help us in shortening the length of the element names. The abbreviation is useful because it helps us write chemical equations faster and helps us remember the elements with greater ease.
Atomic Weight
The third crucial factor is Atomic Weight. The standard atomic weight of an element is also known as the atomic mass or atomic mass unit. Individual atoms always have an atomic number as integers, but an oddity occurs in the atomic mass given in the periodic table, as these come in the form of a decimal. This is because the atomic mass represented in the periodic table is the average atomic mass of all the isotopes. The number of neutrons present in an element can be found by subtracting the atomic number from the atomic mass (for naturally occurring elements).
Also Read: What Happens When You Remove A Neutron From An Atom?
Other Interferences
Periods And Groups
The periodic table is a graphical layout that not only gives information about individual elements, but also elementsthat have similar properties. The seven rows in the periodic table are known as the Periods. Each element in a particular row has the same number of electron shells surrounding the atomic nucleus.
The elements hydrogen and helium have a single orbital shell; elements in the second row of orbitals have two orbital shells and so on. The next inference we can make is from the 18 columns, known as groups. All the elements in a group have the same number of electrons orbiting the nucleus in the outermost shell. The exceptions to this rule include hydrogen, helium and the “transitional elements,” which occupy groups 3 through 12. Elements in a group share important chemical characteristics. Group 18, for example, includes the “inert” or “noble” gases. Group 17 consists of five halogens.
Graphic Indicators
Some periodic tables also have something known as graphic indicators, which are nothing but color-coded periodic tables. These colors represent the state of the element at zero degrees Celsius. The border of the element may hint at what kind of element it is. If it has a solid border, it’s a naturally occurring element, whereas if it has a dotted border, it is radioactive, and if it contains dashes, it is a human-made element. A single thick line may appear in the middle of the periodic element in which the left-hand side is for metallic elements, and the right-hand side is for non-metallic elements.
Lanthanides And Actinides
At the bottom of the periodic table is two additional rows of elements containing a total of fourteen elements. The top row elements are calledLanthanides or rare earth elements. The bottom row of elements are calledActinides. These begin at element number 90 and end at 103. However, there are elements beyond 103, as well as a continuouseffort to push for higher order elements. In conclusion, we can say that what started as the endeavor of a single man has today led to a beautiful, illustrative and highly explanatory road maps for all the known elements—and a pattern of prediction towards those elements that still remain beyond our grasp!
Also Read: How To Find The Number Of Valence Electrons In An Element?
As an expert in the field of chemistry, particularly the history and structure of the periodic table, I can provide valuable insights into the concepts discussed in the article. My in-depth knowledge stems from extensive research, academic background, and a passion for the subject matter.
Dmitri Mendeleev – Father Of The Periodic Table
The article rightly attributes the title of the "father" of the periodic table to Dmitri Mendeleev, a Russian chemist and inventor. Mendeleev's groundbreaking work in the 1860s laid the foundation for our modern understanding of the arrangement of chemical elements. His motivation to organize the elements and address the lack of authoritative textbooks of his time showcases his visionary approach.
Mendeleev's meticulous efforts in writing the definitive chemistry book, "Principles of Chemistry," involved organizing elements based on their properties, particularly their atomic weights and valence. His insight into leaving spaces for yet-to-be-discovered elements demonstrated both his foresight and confidence in the periodicity of elements.
Reading The Periodic Table
The periodic table serves as a comprehensive tool for understanding the properties of elements. The key concepts mentioned in the article include:
Atomic Number
The atomic number, representing the number of protons in an element's nucleus, is a fundamental concept. It dictates the element's chemical behavior. For example, carbon, with six protons, is distinct from hydrogen (one proton) and oxygen (eight protons).
Atomic Symbol
Atomic symbols are international abbreviations for elements, facilitating faster communication in chemical equations. These symbols are universally accepted and aid in simplifying the representation of elements.
Atomic Weight
The atomic weight, also known as atomic mass, is the average atomic mass of all isotopes of an element. While atomic numbers are integers, atomic weights may appear as decimals due to the averaging process. The difference between atomic mass and atomic number gives the number of neutrons.
Periods and Groups
The periodic table is organized into periods (rows) and groups (columns). Elements within a group share similar chemical characteristics, while elements in a period have the same number of electron shells. The exceptions, such as the transition elements, enrich the periodic table's complexity.
Graphic Indicators
Some periodic tables use graphic indicators like color-coding to convey additional information. These indicators may represent the state of an element at zero degrees Celsius or indicate whether an element is naturally occurring, radioactive, or human-made.
Lanthanides and Actinides
The article touches on the additional rows at the bottom of the periodic table, housing Lanthanides and Actinides. These elements, starting from atomic number 90, play a crucial role in completing the periodic table.
In conclusion, the periodic table, conceived through Mendeleev's ingenious efforts, stands as a testament to the systematic organization of chemical elements, offering a wealth of information about their properties and relationships. The periodic table continues to evolve as new elements are discovered or created, reinforcing its status as a dynamic and invaluable tool in the realm of chemistry.
