The strongest acid is H₃Sb and the weakest acid is H₂Se because the acid strength for a binary acid (HX) increases with electronegativity of X and size of X.

The strongest acid is H₂Te and the weakest acid is H₃As because the acid strength for a binary acid (HX) increases with electronegativity of X and size of X.

The strongest acid is H₃As and the weakest acid is H₂Te because the acid strength for a binary acid (HX) decreases with electronegativity of X and size of X.

The strongest acid is H₂Se and the weakest acid is H₃Sb because the acid strength for a binary acid (HX) decreases with electronegativity of X and size of X.