# For which phase change does water absorb the most energy?

The numbers you want are called the molar heat of fusion, which gives us the energy needed to cause melting (at the melting point, without change in temperature). For water, this is $6.02 \frac{k J}{\text{mole}}$
You also want to molar heat of vapourization, which is the energy needed for the liquid to vapour change. For water, this is $40.7 \frac{k J}{\text{mole}}$.