The heat transferred to the ice increases the thermal energy of the molecules of water. Why does this cause a change in state?

It creates a change in state because the heat starts to slowly melt the ice.

Explanation:

I took a test.

As energy is transferred to the water molecules in the ice, the motion of the molecules increases. The motion of the molecules increases enough that it overcomes the attractions the water molecules have for each other causing the ice to melt.

it should be p1 v1 = p2 v2