Final answer:
As you move right across the periodic table, binary acidity increases due to the increasing electronegativity of nonmetal atoms and resulting greater polarity of the H-A bond.
Step-by-step explanation:
As you move right across the periodic table, binary acidity increases. This is because the acid strength of binary hydrogen compounds, such as those formed with nonmetals, increases with the electronegativity of the nonmetal atom. As electronegativity increases, the polarity of the H-A bond also increases, facilitating the release of a proton (H+) and therefore increasing acidity.
Across the second row, for example, the order of increasing acidity is methane (CH4) < ammonia (NH3) < water (H2O) < hydrogen fluoride (HF). Similarly, across the third row, the order is silane (SiH4) < phosphine (PH3) < hydrogen sulfide (H2S) < hydrogen chloride (HCl).