Which is the correct thermal stability order of `H_(2)E(E=O,S,Se,Te` and `Po)`?

Options

A. `H_(2)SeltH_(2)TeltH_(2)PoltH_(2)OltH_(2)S`
B. `H_(2)SltH_(2)OltH_(2)SeltH_(2)TeltH_(2)Po`
C. `H_(2)OltH_(2)SltH_(2)SeltH_(2)TeltH_(2)Po`
D. `H_(2)PoltH_(2)TeltH_(2)SeltH_(2)SltH_(2)O`

Answer

D

Explanation

In oxygen family down the group thermal stability decreases order of thermal stability
`H_(2)O>H_(2)S>H_(2)Se>H_(2)Te>H_(2)Po`
This is because H-M bond dissociation energy decreases down the group with the increase in the size of central atom.