(i) P and S; ionic radii larger than their atomic radii II gain of electrons causes increase in ionic radius;
(ii) Oxide of R has strong ionic bonds with giants ionic structure; while oxide of S has weak vander waals forces with simple molecular structure;
(iii) P and Q; P is a non-metal with the smaller atomic radius hence most electronegative;Q is a metal with the largest atomic radius hence most electropositive;
sharon kalunda answered the question on May 21, 2019 at 12:15
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