Why is `H_(2)O` a liquid and `H_(2)S` a gas ?

Explanation

The difference in electronegativity values of O (3.5) and H(2.1) is more than the difference between the electronegativity values of H (2.1) and S(2.5) i.e., O - H bond is more polar than S - H bond. That is why H-bonding is present among water molecules but absent in `H_(2)S`. Thus,
strong intermolecular interactions causes water to exist as a liquid but due to weak van der waals' force `H_(2)S` exists as a gas.
`"---H"-underset(H)underset(|)O"---"H-underset(H)underset(|)O"---"H-underset(H)underset(|)O"---"`