What is Modern Periodic Law?

Dmitri Mendeleev, a Russian chemist, observed a pattern among the elements: as their atomic masses increased, their chemical and physical properties repeated with prior elements. He named this property Mendeleev’s Periodic Law. However, this law was not accurate for all elements, as only 63 were known at the time.

In an effort to improve upon Mendeleev’s Periodic Law, Henry Moseley proposed the Modern Periodic Law, which states that 

“The physical and chemical properties of the elements are periodic functions of their atomic numbers.” 

The atomic number is considered the number of protons or electrons in a neutral element. Through extensive advancements and research in the field of science, we now have a wealth of knowledge about atoms, their behaviours, and their properties. With this knowledge, scientists can now classify and pair elements with similar properties with ease that Mendeleev could never have imagined. These advancements have resulted in the form of the Modern Periodic Table.

Moseley Law

Modern periodic law is sometimes also called Moseley Law as it was given by Henry Moseley hence the name Moseley law, which states that,

“Various properties of the chemical elements whether Physical or Chemical are periodic functions of its  atomic mass.”

All matter in our environment is made up of basic units known as elements. Initially, only 31 chemical elements were discovered in 1800 and it was easier to study their chemical and other properties. However, as more and more elements were discovered due to technological advancements in science, it became harder to study all the elements simultaneously. Scientists began to think about a method to simplify the study of elements in order to make their work easier.

It was observed that elements’ properties have periodicity, and to study the properties of elements in a fixed pattern, many tables were created to arrange the elements in an ordered manner based on their characteristics. Some examples of these are Doberiener’s triads, Newland’s octaves, Mendeleev’s periodic table, etc.

Significance of the Periodic Classification of Elements

• The classification of elements into groups provides us with a fixed pattern in which the elements’ properties change on a regular basis. The periodic table simplified and organized the study of elements’ physical and chemical properties. We can now simply go to the group and see the properties of the periodic table elements or predict the properties of an element if we know the properties of other elements in the same group.
• Despite the fact that so many elements have already been discovered, there is still a chance that new elements will be discovered. Scientists can use a periodic table to learn about the trending characteristics of elements based on their properties, and thus distinguish new elements from existing ones. Furthermore, researchers are constantly striving to discover new elements and investigate their properties.