Final answer:
The acidity of oxyacids increases as you move from left to right across a period on the periodic table, correlating with the increasing electronegativity of the central atom and the inductive effect caused by additional oxygen atoms.
Step-by-step explanation:
The acidity of oxyacids increases to the right across a period on the periodic table. This trend is related to the electronegativity of the central atom in the molecules and the inductive effect of oxygen atoms. As the number of oxygen atoms in an oxyacid increases, they exert a greater inductive effect by withdrawing electron density from the O-H bond, thereby increasing the acidity of the compound. Similarly, as the electronegativity of the central atom increases, the electrons are drawn more strongly towards the central atom, again weakening the O-H bond and increasing the acid strength of the oxyacid.
Systematically, the number of terminal oxygen atoms tends to increase as we move from left to right across the periodic table. Moreover, oxyacids that contain a higher oxidation number of the central element have greater acidity. Hence, as we go from left to right across a period, the electronegativity of the central element generally increases, resulting in a successive increase in acid strength, as seen from H3PO4 (a weak acid) to HClO4 (one of the strongest acids known).