I need help with chemistry please?

Question

What does the atomic radius tell us about the atom?
Why is the picometer used to measure the radius of an atom?
Why not use a micrometer or a femtometer?

Answer 1

The atomic radius is the distance from the atomic nucleus to the outmost stable electron orbital in a atom that is at equilibrium.
it is generally measured in picometer (10^-12)or Ao(10^-10)

Answer 2

The atomic radius is the distance from the atomic nucleus to the outermost stable electron orbital in an atom that is at equilibrium. It is measured in picometers or angstroms. Since electrons are constantly moving, measuring the outermost energy level is difficult.