Q. Consider the following statements with reference to the Periodic Table of chemical elements:1. Lonisation potential gradually decreases along a period.2. In a group of elements,electron affinity decreases as the atomic weight         increases.3. In a given period, electronegativity decreases as  the atomic number           increases.Which of these statement(S) is/are correct ?

1. 1 only
2. 2 only
3. 1 and 3
4. 2 and 3