Q.9:- What does atomic radius and ionic  radius really mean to you?

Answer:-

Atomic radius:-  The distance from the centre of nucleus to the outermost shell o electrons in the atom of any element is called its atomic radius. It refers to both covalen or metallic radius depending on whether the element is a non-metal or a metal.

Ionic radius:- The Ionic radii can be estimated by measuring the distances between cations and anions in ionic crystals.