Question

How to rank the atoms in each group in order of increasing size?

Answer 1

a. Si, S, Mg: all in period 3, size decreases from left to right therefore S < Si < Mg b. Kr, Ne, Xe: all in group 18, size increases down a group therefore Ne < Kr < Xe c. B, C, Ne: all in period 2, size decreases from left to right therefore Ne < C < B