question_answer 35)

    Which of the following gives the correct increasing order of the atomic radii of 0, F and N? (a) O, F, N                            (b) N, F, O                           (c) O, N, F                            (d) F, O, N

Answer:

               (d) As we move from left to right in a period, the atomic number of each succeeding element increases by 1. So, the electrons are attracted close to the nucleus and hence, the atomic size decreases, along a period from left to right. Therefore, the increasing order of radii is F, O, N as atomic number of F, O and N are 9, 8 and 7 respectively. Due to which F belongs to 17thgroup. O belongs to 16thgroupand N belongs to 15thgroup