How do you calculate the atomic radius for Argon?:confused:

How have you been taught to do it? It doesn't have a well defined radius, as the electrons form a cloud that does not have an edge to it, but instead has an exponential drop in probability. (kind of like the earth's atmosphere, it just peters off into space)

There are different ways of making a quantitative calculation which will have a certain interpretation, which have you been taught?