question_answer 93)

  Match the correct radius with the element. Element             Atomic radius (pm) (i) Be                     (a) 74 (i)  C                       (b) 88 (iii) O                   (c) 111 (iv) b                    (d) 77 (v) N                      (e) 66

Answer:

    Be = 111, C = 77, O = 66, B = 88, N = 74 All the five elements belong to the same period (second period). The atomic radii in a period decrease as the effective nuclear charge increases.                 \[\underset{111}{\mathop{Be}}\,>\underset{88}{\mathop{B}}\,>\underset{77}{\mathop{C}}\,>\underset{74}{\mathop{N}}\,>\underset{66}{\mathop{O}}\,\]