Question

For water, the melting and boiling points occur at:

a) Freezing; 100°C
b) Boiling; 0°C
c) Freezing; 0°C
d) Boiling; 100°C

Answer 1

The freezing point of water is 0°C and the boiling point is 100°C on the Celsius scale. The correct answer to the student's question is c) Freezing; 0°C and d) Boiling; 100°C.

Step-by-step explanation:

For water, the melting point occurs at 0°C, which is when water changes from solid ice to liquid. Conversely, the boiling point of water occurs at 100°C, at which it changes from a liquid to a gas (steam). Therefore, the correct answer to the question is: c) Freezing; 0°C and d) Boiling; 100°C.

The Celsius scale is used here, where these points are defined: 0°C as the freezing point and 100°C as the boiling point of water. Importantly, at these temperatures, provided the atmospheric pressure is one atmosphere, water can exist in two phases simultaneously - as a solid and liquid at 0°C and as a liquid and gas at 100°C.