Does the basicity of hydrides increase with larger atom size?

[AdityaDev]

I am confused with the statement given by a website (http://www.chem.ucalgary.ca/courses/351/Carey5th/useful/acidbase.html

"Size. When comparing atoms within the same group of the periodic table, the larger the atom the weaker the H-X bond and the lower the electron density making it a weaker base."

When A-H bond becomes weaker, the production of A^- becomes easier, so electron density on A increases. Hence the base has to be stronger right?

 

[Borek]

the production of A- becomes easier, so electron density on A increases

I don't see how the latter comes from the earlier. Electron density is not a function of how easily the bond is broken.

Or perhaps what you mean is that after the proton is removed, electron density on the conjugate base left is higher than it was before the reaction? Sure, that's true. But still the final electron density depends on the size of the conjugate base, and we are comparing different bases comparing their final electron densities.