What structures are formed when water molecules surrounds individual ions

They form cations.

Explanation:

For example, cations such as Na +, K +, or Mg + + surround themselves with the water molecules with which they bind through dipole interactions; the oxygen atoms in the water molecule are oriented towards the cation. Other cations like Fe3 + bind to 6 water molecules through very strong bonds.

Answer: Cations (positively charged ions) are surrounded by the negative dipole of the water molecule and the anions (negatively charged ions) are surrounded by the positive dipole of the water molecule. A lattice structure is formed when water molecules surrounds individual ions.