Question

why H2O is liquid and H2S is gas at room temperature​

Answer 1

In H2O there is hydrogen bonding. Hydrogen bonding occurs only when H is bonded with an element having ELECTRONEGETIVITY MORE THAN OR EQUAL TO THREE as O has EN=3.5 hydrogen bonding occurs in H2O but S has EN less than 3 so no H bonding occurs in H2S

Answer 2

because the melting point of H2S is less than the room temperature and melting point of H2O more than the room melting.

hope this will be enough.