The atomic radii of the elements of second period are given below:

(a) Arrange these elements in the decreasing order of their atomic radii (Keeping the element with the largest atomic radius first).
(b) Are the elements now arranged in the pattern of a period in the periodic table?
(c) Which elements have the largest and the smallest atoms?
(d) From this data, infer how the atomic size (or atomic radius) of the elements changes as you go from left to right in a period?

Explanation

(a) In the above given problem, the largest radius `152"pm"` is of `Li` (Lithium), So `Li` should be placed first. This should be followed by `Be(111 "pm"), B(88"pm"),C(77"pm"),N(74"pm"),O(6"pm")` and `F(64"pm")`. We can now arrange the given elements in the decreasing order of their atomic radii as follows:

(b) Yes, the elements are now arranged in the pattern of a period of periodic table.
(c) The element `Li` ( Lithium) has the largest atom radius 152 pm) whereas element `F` ( Fluorine) has the smallest atom (atomic radius 64pm).
(d) From the above arrangement of elements with their atomic radii, that the atomic radius (or atomic size) decreases on moving from left to right in a period of the periodic table.