What happens to the acidity of nonmetal hydrides as you move down the periodic table?

The correct understanding of the trend in acidity of nonmetal hydrides as you move down the periodic table is that acidity actually increases. This trend occurs because, as you descend a group in the periodic table, the size of the nonmetals increases, which results in longer and weaker bond lengths between the hydrogen atom and the nonmetal atom in the hydride. Consequently, these bonds become easier to break.

A significant factor influencing acidity is the stability of the conjugate base formed when the hydride donates a proton (H+). As the size of the nonmetal increases down the group, the resulting conjugate base becomes larger and can better accommodate the negative charge, thus stabilizing it. This enhanced stability of the conjugate base correlates with a stronger tendency of the original hydride to donate a proton, leading to increased acidity.

For example, consider the nonmetal hydrides of the halogens: HF (hydrofluoric acid), HCl (hydrochloric acid), HBr (hydrobromic acid), and HI (hydroiodic acid). As we move from HF to HI, we see that the acidity increases in the following order due to the reasons outlined.

Hence, the observation that acidity increases as