Solution:

• The United Nations General Assembly during its 74th Plenary Meeting proclaimed 2019 as the International Year of the Periodic Table of Chemical Elements on 20 December 2017. Based on the 202 EX/Decision 43, the IYPT2019 was adopted by the UNESCO General Conference at its 39th Session.
• It is to highlight the first publication of Periodic Table.
• Dmitri Ivanoich Mendeleev Tabulated the elements in his Periodic Table in 1869.
• In 2019, it marks the 150 anniversary of the first publication of periodic table by Mendeleev.