The group of elements responsible for hydride gap

What is hydride gap?

Explain how acid strength changes among i. the hydrides of the group elements and (ii) the hydrides in the same row of the periodic.

In group-16 the element whose hydride is neutral in nature is

Assertion : Acidity of hydrides of group 16 elements increases down the group. Reason : Electronegativity of these elements increases down the group.