what is radius of atom

the distance from nucleus to the last shell of the atom

diameter of atom is from 0.1 to 0.5 nanometers.
radius is 0.25 nanometers

their cant be a fixed radius as every atom may have different no. of elctrons which maker every atom unique you can ask the size of the atom 





as per my thinking   @IHOPE THIS HELP@

Atoms(Element) doesn't have radius because, it is not a spherical thing.