Consider the following statements with reference to the Periodic Table of chemical elements: I. lionisation potential gradually decreases along a period. II. In a group of elements, electron affinity decreases as the atomic weight increases. III. In a given period, electronegativity decreases as the atomic number increases. Which of these statement(s) is/are correct?

I. Ionisation potential (or Ionization energy) is the energy required to remove an electron from an atom. It generally increases along a period (from left to right) due to increasing nuclear charge and decreasing atomic size, making it harder to remove an electron. Statement I is false. II. Electron affinity is the energy change when an electron is added to a neutral atom to form a negative ion. In a group, as atomic weight (and atomic number/size) increases down the group, the nucleus's attraction for an incoming electron decreases due to increased distance and shielding effect. Thus, electron affinity generally decreases down a group. Statement II is correct. III. Electronegativity is the measure of an atom's ability to attract electrons in a chemical bond. In a given period, electronegativity generally increases as the atomic number increases (from left to right) due to increasing nuclear charge and decreasing atomic size. Statement III is false.