Hydrogen sulfide (H2S) is a polar molecule. A molecule's polarity is determined by the electronegativity difference between its constituent atoms and the overall molecular geometry.
In hydrogen sulfide, sulfur (S) is more electronegative than hydrogen (H). As a result, the shared electrons in the H-S covalent bonds are pulled closer to the sulfur atom, creating a partial negative charge on sulfur and partial positive charges on the hydrogen atoms. This distribution of charges leads to an uneven distribution of electron density within the molecule, making it polar.
The molecular geometry of hydrogen sulfide is bent or V-shaped, with the sulfur atom at the center and the hydrogen atoms positioned on either side. The bent shape further contributes to the polarity of the molecule.
Overall, due to the presence of polar covalent bonds and the bent molecular geometry, hydrogen sulfide is considered a polar molecule.