For tetrahedral coordination the radius ratio r r should be

id state 10 Sol. For an atom or an ion to be present into a tetrahedral void the radius ratio should be 0.225 0.414 r r Hence the correct answer is option (d) 67. AB is an ionic solid. If the ratio of the ionic radii of A+ and B– is 0.52, what is the coordination number of B– ? (a) 2 (b) 3 (c) 6 (d) 8 The radius ratio is = 0.52 Which is between 0.414-0.732 Hence the coordination number is 6 Hence the correct answer is option (c)