The temperature of a substance ____ as its heat of fusion is added to melt the substance
A. increases
B. decreases
C. remains constant
D. fluctuates from rapid increases and decreases
remains constant
The correct answer is C. remains constant.
When a substance changes from a solid to a liquid, it undergoes a phase change called melting. During this phase change, the heat of fusion is added to the substance. The heat of fusion represents the amount of heat energy required to convert a given amount of substance from a solid to a liquid without changing its temperature.
When the heat of fusion is being added, it is utilized to break the intermolecular forces holding the particles of the substance in a fixed regular pattern. As these forces are overcome, the substance transitions from a solid to a liquid state.
During this process, the temperature of the substance remains constant even though heat energy is being added. This is because all the heat energy is being used to convert the substance from a solid to a liquid rather than increasing its temperature. Once the substance is completely melted, the temperature can start to rise again.
Therefore, the temperature remains constant as the heat of fusion is added to melt the substance.