• # question_answer The  Order of increasing sizes of atomic radii among the elements O, S, Se and As is:     JEE Main  Online Paper (Held On 22 April 2013) A)  $As-S<O<Se$    B)  $Se<S<As<O$C)  $O<S<As<Se$   D)   $O<S<Se<As$

On moving down in a group atomic radii increases due to successive addition of extra shell hence $O<S<Se$ Further As is in group 15 having one less electron in its p orbital hence have higher atomic radii than group 16 elements. i.e., $O<S<Se<As$