How do we know that ice gains heat during melting?

We know that ice gains heat during melting through the observation of physical and chemical changes that occur when heat is applied to ice. Here's how you can understand and demonstrate this concept:

1. Gather the necessary materials: a heat source, ice cubes, a thermometer, and a container (such as a beaker or a cup) to hold the ice.

2. Start by measuring and recording the initial temperature of the ice. This will serve as a baseline for comparison.

3. Place the ice cubes in the container and closely monitor the temperature while applying heat to the ice. The heat source could be a Bunsen burner, a stove, or simply warm hands.

4. Continuously measure and record the temperature of the ice as it begins to melt. You will notice that the temperature remains constant at 0 degrees Celsius (32 degrees Fahrenheit) until all the ice has melted.

5. Once the ice has completely melted, continue applying heat and monitoring the temperature. You will observe that the temperature gradually starts to rise above 0 degrees Celsius.

These observations provide evidence that the ice gains heat during the melting process. The temperature of the ice remains constant at 0 degrees Celsius until all the ice has melted because the heat energy being transferred from the heat source is utilized to break the intermolecular bonds holding the ice molecules together. This energy goes into changing the state of water from a solid (ice) to a liquid (water), rather than raising the temperature.

Once all the ice has melted, the heat energy can then cause the temperature of the water to rise. This demonstrates that heat is indeed transferred to the ice during the melting process, resulting in an increase in its temperature.