Oxygen and sulfur have similar chemical properties because both elements have six electrons in their outermost electron shells. indeed, both oxygen and sulfur form molecules with two hydrogen atoms: water and hydrogen sulfide. surprisingly, water is a liquid, yet hydrogen sulfide is a gas, even though sulfur is much larger and heavier than oxygen. propose an explanation for this striking difference.

Electro negativity and polarity of the bond in the both molecules

Explanation:

Approaching the matter from an electro negativity perspective, oxygen is more electronegative than sulphur. This implies that the O-H bind is more polar than the S-H bond.

The high polarity of the O-H bond leads to a higher degree of hydrogen bonding in H2O than in H2S. This higher degree of hydrogen bonding in H2O leads to greater intermolecular association and the substance is a liquid. Hence H2O is liquid but H2S is a gas.

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.

it would be a gas formation