Table of contents


What is Periodic Table?

Up Till now, 118 elements are known to man - 94 of them found in nature while the remaining 24 are made within the laboratories. These elements are arranged in a tubular style according to their increasing atomic numbers within a table called the Periodic table of elements.

However, it's not that the scientists put all the elements randomly to this table; instead, all the elements were arranged according to their periodic characteristics and atomic numbers.

Periodic table is also used for balancing chemical equations during a chemical reaction if you are doing it manually. However, if you are using balancing equation calculator you will still need that periodic table for doing it correctly.

Related: Learn how to balance redox reaction in basic solution.

History of the Periodic Table

To arrange all the known elements with that much preciseness and accuracy, the scientists had to work hard for about a complete century. Since various scientists worked on this project of assembling elements, the table kept on changing its shape and size such as,

Related: Simple ways for balancing complex chemical equations.

Related: Learn about endothermic and exhothermic reactions and the general chemical equation.

Related: Learn the complete process of sodium reaction with chlorine and making of sodium chloride.

Related: Find what you need to know about synthesis reaction in chemistry.

  • Lavoisier's Periodic Table

    If we see the history of the periodic table, The first periodic table of elements was structured by a French scientist Antonie Lavoisier in 1789. He grouped the elements into two main classes - Metals and Non-metals.

  • Dobereiner's Periodic Table

    After forty years of this periodic table, another scientist Johann Wolfang Dobereiner grouped the elements into three groups based on their similar chemical and physical properties. He called these three groups triads.

    He also proposed that the elements of the middle group possess the properties average to that of the other two groups.

  • John Newlands Periodic Table

    In 1860, after discovering the atomic mass, British scientist John Newlands arranged the known elements based on their increasing atomic masses.

    After assembling all the elements in the table, he noticed that every group of eight elements showed similar properties. He named his finding the law of octaves. The only drawback of the Newlands periodic table of elements was that it didn't possess any space for undetected elements.

  • Mendeleev Periodic Table

    In 1866, Russian scientist Dmitri Mendeleev removed these errors and left gaps for undiscovered elements. His periodic table was the closest form of today's periodic table.

    However, he also arranges the elements based on their atomic masses. The surprising thing was that he even predicted the nature of an undiscovered element (eka-aluminum at that time) that was needed to fill the gap in the table. Use this tool for calculating atomic mass.

    Afterward, an element was discovered possessing the same properties Mendeleev described before, and today, the world knows that element as Gallium.

    However, mendeleev periodic table also contained some errors like controversial positions of some elements. That's why Mendeleev periodic table was also rejected.

  • Moseley's Modern Periodic Table

    In 1913, Henry Moseley discovered subatomic particles and gave the concept of atomic number. After that, he arranged the elements according to their atomic numbers.

    Moseley's periodic table was the answer to all the confusion, and this is the same periodic table we use today.

Related: Find out the complete process of a metal displacement reaction in an aqueous medium.

Basic Properties of Periodic Table

The following properties of periodic table are available for look up or trend visualization of periodic table of elements:

  • The periodic table is a kind of 8×17 grid that is being placed over two separate rows.
  • Each element is represented by its atomic symbols in the table. The atomic mass and the atomic number of each element are written beside its symbol.
  • As stated before, these elements are arranged according to the increasing atomic numbers. These atomic numbers increase from left to right, and we call these horizontal rows periods.
  • On the other hand, the vertical columns of the periodic table are called groups. Remember that all the elements enlisted in a single group possess similar properties.
  • There are seven groups and eighteen periods in the periodic table. Some of the groups and periods are also named specifically like alkali metals group (I), alkaline earth metals group (II), halogen group(XVII), and noble gases group (XVIII). Similarly, the last two periods are also called lanthanides and actinides.
  • Besides periods and groups, the periodic table is divided into four blocks (s,p,d,f) based on the location of the valence electron of an atom. For example, all the atoms of block s possess the valence electrons in subshell "s" and so on.

Related: What are gas laws and how these laws are used in the real life?

Why is the Periodic Table Important?

If we say that the periodic table is nothing but just a table of elements, we would be wrong. There is a great importance of periodic table which enables the scientists to do so many complicated things just in a glance, such as

  1. Predict the nature of chemical reactions conducted by each element
  2. Analyze reactivity of each element and order of reactivity
  3. Understand how the chemical properties of all the elements are different periodically from each other
  4. Assume the properties and nature of yet-to-discover elements.
  5. Study the atomic structure of each element and check the similarities and dissimilarities among elements
  6. Design the chemical reactions to get the desired cosmetic and pharmaceutical products.

On a final note, we can say that this periodic table of elements is not just a catalog or guide of the known elements; instead, it is a window that opens up to the entire universe and helps us understand the realm around us.