When a bottle of water is placed in a freezer, it cools down and eventually freezes. During this process, the water is losing thermal energy. Thermal energy is the energy that comes from the temperature of the substance, and it flows from warmer areas to cooler areas. As the water in the bottle comes into contact with the cold air inside the freezer, it begins to lose heat to that cooler environment. This loss of thermal energy causes the temperature of the water to drop until it reaches its freezing point and transforms into ice.
To determine that the water is losing thermal energy, we can observe the changes in temperature. If we were to measure the temperature of the water at intervals, we would see a decrease in temperature until it falls to 0 degrees Celsius (32 degrees Fahrenheit) at which point it starts freezing. Therefore, it’s clear that the water molecules are losing thermal energy as they slow down and arrange themselves into a solid structure.
Additionally, it is important to consider the principle of energy conservation. Energy cannot be created or destroyed; it simply changes forms. When the water in the bottle loses thermal energy, that energy does not disappear. Instead, it is transferred to the surrounding environment of the freezer. The freezer itself is designed to remove heat from the items inside it and expel that heat out into the surrounding air, keeping the interior of the freezer cold. So, in essence, the thermal energy is moving from the water to the freezer air, leading to the water freezing.