For the following questions answer them individually
The President of which of the following countries was invited as the Chief Guest for the Republic Day parade on 26 January 2020?
Which radioactive element with atomic number 43 in the modern periodic table is unstable, and the half-lives of all its isotopes are relatively short, from 4.2 million years to 5.0 s?
The Himalayas have been divided on the basis of regions from west to east. The correct order of regions from west to east is:
Which chemical element of Group 18 of the periodic table is produced by the natural radioactive decay of uranium in soils and rocks?