From UPSC perspective, the following things are important:
Prelims level: Basic knowledge of the Periodic Table
Mains level: Not Much
- The International Year of the Periodic Table of Chemical Elements was launched on January 29, 2019, at the headquarters of UNESCO in Paris.
- The UNESCO stated that the events and activities will be held throughout the year in order to mark 150 years of the formation of the periodic table.
- Dmitri Mendeleev was the man who published the periodic table for the first time in 1869.
The modern Periodic Table
- The periodic table is an arrangement of all the elements known to man in accordance with their increasing atomic number and recurring chemical properties.
- They are assorted in a tabular arrangement wherein a row is a period and a column is a group.
- Until 1863, the world was aware of only 56 known elements.
- The rate of scientific progress was such that every year, a new element was being discovered.
- It was during this time that Mendeleev came up with the idea of the Periodic Table.
- He published the Periodic Table in his book– The Relation between the Properties and Atomic Weights of the Elements.
- Mendeleev said that he arrived at the idea in his dream, where he saw all chemical elements falling into place on a table according to their chemical properties.
- Mendeleev had found a definitive pattern following which, each element could be placed according to their atomic weight.
- He had also predicted the qualities of the ‘missing’ (yet to be discovered) elements and gave them Sanskrit names.
- The noble gases including helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn) were added to the table between 1895 and 1901.
- Likewise, additions have been made to the periodic table as new elements have been discovered in the last hundred years
- In 1914, English physicist Henry Gwyn-Jeffries Moseley found out that each atomic nucleus can be assigned a number, according to the number of protons in that atom.
- This changed the way the periodic table worked. The table was redesigned according to the atomic number of elements rather than their atomic weight
- Rare-earth elements, including the elements in the Lanthanide series, were included in the atomic table in the late 19th century.
About the UNESCO event
- The year 2019 was declared as the International Year of the Periodic Table of Chemical Elements (IYPT 2019) at the 74th Plenary Meeting.
- The event will highlight the importance of periodic table in various science disciplines.
- Scientists and representatives of the private sector will came together for the event.
Aim of the International Year of Periodic Table of Chemical Elements
- The fundamental motto of IYPT 2019 is to recognize the importance of periodic table of chemical elements as one of the most important and influential achievements in modern science.
- The periodic table reflects the essence of all basic science disciplines like- physics, biology and chemistry.