* Asymmetrical shape: The phosphate ion (PO₄³⁻) has a tetrahedral shape with four oxygen atoms surrounding the phosphorus atom. The addition of a hydrogen atom to one of the oxygen atoms introduces an asymmetry to the molecule.

* Electronegativity difference: Oxygen is more electronegative than both phosphorus and hydrogen. This means that the oxygen atoms pull electron density away from the phosphorus and hydrogen atoms, creating partial negative charges on the oxygen atoms and partial positive charges on the phosphorus and hydrogen atoms.

* Dipole moment: The uneven distribution of electron density results in a net dipole moment, making the molecule polar.

Therefore, due to its asymmetrical shape and the presence of polar bonds, hydrogen phosphate is considered a polar molecule.