In mixture of ice and water,ice is in solid phase and water is in liquid phase.So it is a heterogeneous system. Homogeneous stands for one or more substances in same state but thoroughly spread or mixed. When you add ice, or frozen water, to pure water, you have created a heterogeneous mixture of a pure substance. A heterogeneous mixture is one in which the distribution of components is unequal. The atoms in the ice are locked in a crystalline matrix whose atoms are less densely packed than those in the liquid water, a unique property of water. The atoms of water are distributed differently in the ice from in the liquid water, and the ice can be physically separated from the water, making it a mixture. Once the ice melts, the two can no longer be separated, so it is no longer a mixture. So ice and water is a heterogeneous mixture.