The bonds in H2Se (Hydrogen Selenide) are considered polar. This can be understood by examining the electronegativity differences between the atoms involved.
In H2Se, selenium has a higher electronegativity than hydrogen. This means that selenium attracts the shared electrons more strongly than hydrogen does. As a result, the electron density around the selenium atom becomes greater, giving it a partial negative charge (δ-), while the hydrogen atoms acquire a partial positive charge (δ+).
The molecular geometry of H2Se is bent due to the presence of lone pairs on the selenium atom, which further enhances the polarity of the molecule. Because of this bent shape and the unequal sharing of electron density, the overall dipole moments do not cancel out, resulting in a polar molecule.
In summary, H2Se features polar bonds due to the differences in electronegativity between hydrogen and selenium, combined with its bent molecular shape.