The H-S bond is polar. This is because hydrogen (H) and sulfur (S) have different electronegativities. Electronegativity is a measure of how strongly an atom attracts electrons towards itself in a chemical bond.
Hydrogen has an electronegativity of approximately 2.20, while sulfur has an electronegativity of about 2.58. The difference in electronegativity between hydrogen and sulfur is 0.38, which is enough to create a polar bond. In a polar bond, the electrons are not shared equally, leading to a slight charge separation. In the case of the H-S bond, sulfur, being more electronegative, attracts the shared electrons more strongly, resulting in a partial negative charge (δ-) on sulfur and a partial positive charge (δ+) on hydrogen.
Therefore, the H-S bond is polar due to the difference in electronegativity between hydrogen and sulfur.