Question

ÅIn group I of the periodic table, three elements X, Y, and Z have ionic radii 1.33 Å, 0.95 Å and 0.60 Å respectively. Giving a reason, arrange them in the order of increasing atomic number in the group.

Answer 1

As we move down a group, the number of shells increases, and hence the atomic size increases. Therefore, Z will have the smallest atomic number followed by Y, while X will have the largest atomic number. So the elements in order of increasing atomic number will be Z < Y < X.