Which of the following sets of elements are arranged in order of decreasing atomic size in the Periodic Table?
6C, 4Be, 7N,8 O
4Be,6 C,7 N,8 O
8O, 7 N, 6C, 4Be
7N, 8O, 6C,4Be
Correct answer is B
\(_4Be\), \(_6C\), \(_7N\), \(_8O\) is the answer because atomic size decreases across the period and increases down the group due to the effect of the positively charged nucleus./ increasing atomic numbers.