Understanding the Concepts
* Heat of Fusion: This is the amount of energy required to change a substance from a solid to a liquid at its melting point. For water, the heat of fusion is 334 J/g (joules per gram).
Calculation
1. Identify the mass of water: You have 2 grams of water.
2. Multiply the mass by the heat of fusion: 2 g * 334 J/g = 668 J
Answer: You need 668 joules of energy to melt 2 grams of water.
