What is the element that is largest MG CI S NA?

Among the elements magnesium (Mg), chlorine (Cl), sulfur (S), and sodium (Na), sodium (Na) is the largest in terms of atomic radius. Atomic size generally increases down a group in the Periodic Table and decreases across a period. Sodium, being in Group 1 and having a lower atomic number than chlorine, has a larger atomic radius. Thus, Na is the largest of the elements listed.