S and 0 are in the same periodic group and share chemical properties, but H 2 S is a gas at room temperature, and H 2 O is a liquid. Which of the following is the main reason for this?

Question

H 2 O has stronger intermolecular bonds than H 2 S

Answer 1

Yes, the answer you typed is the correct answer, but more specifically it is the quite strong intermolecular bond called Hydrogen Bonds. Oxygen is strongly electronegative, and water molecules have very strong hydrogen bonds which attract water molecules together. These give water it's key properties like high surface tension, and a higher boiling point and melting point than would be found if water did not have strong hydrogen bonds. Sulfur is not so strongly electronegative, and so H₂S has very much lower boiling point, making it a gas at standard temperature and pressure.