Question

A substance has a melting point of 80 °C. Which of the following is true for the substance?

Answer 1

Answer:

When the substance is cooled, its temperature will fall below 80 °C after 100% of the liquid has changed to solid.

Explanation:

Melting point is the temperature at which a solid changes state to liquid. At the melting point, the phase of matter changes from solid state to a liquid flowing state.

If after a substance is cooled, without reaching its melting point, it will still remain as a liquid. Below the melting point the substance will freeze back to its solid state.

• For our hypothetical substance whose melting point is  80 °C, it implies that at this temperature, the substance undergoes a phase change from solid to liquid completely.
• The reverse is also the case, below the melting temperature, all parts of the compound changes back to its original solid state.