(a) The elements of the second period along with their atomic numbers in parentheses are given below :
B (5), Be (4), O(8), N(7), Li (3), C (6), F (9)
(i) Arrange them in the same order as they appear in the periodic table.
(ii) Which element has the largest and smallest atom ?
(b) Why does atomic radius change as we move from left to right in a period ?

Explanation

(a) (i) Li (3), Be (4), B (5), C (6), N (7), O(8), F (9)
(ii) The element Li has the largest atom. The element F has the smallest atom. ltbnrgt (b) Along a period, the nuclear charge increases and the electrons are attracted more towards the nucleus. Therefore, the atomic size or atomic radius decreases as we move from left to the right along a period.