Arrange the following elements in increasing order of their atomic radii: `a] Li, Be, F, N " " b] Cl, At, Br, l`

Explanation

a) Li, Be, F and N belong to the same period of Modern Periodic Table. As we move left to right in the periodic table, the atomic radii of elements decreases. Thus these elements arranged in increasing order of atomic radii are:
`F < N <  Be < Li`
. b] Ci, At, Br, and I belong to the same group of the periodic table. As we move down in a group, the atomic radil of elements increase.
Thus these elements arranged in increasing order of atomic radii are: `CI < Br < l < At`.