Question

Consider a physical change to an object. Give one example that demonstrates what happens to mass during a physical change and make a conclusion about the mass of an object that undergoes physical changes.

Answer 1

An excellent example of a physical change that demonstrates what happens to mass is the process of melting ice. When ice (solid water) is heated, it undergoes a physical change and transforms into liquid water.

Before the melting occurs, you can measure the mass of the ice. After it has completely melted into liquid water, you can measure the mass of the water. Importantly, the mass of the melted water is equal to the mass of the ice before melting, assuming no water has escaped or been added during the process.

**Conclusion:** The mass of an object remains constant during physical changes, as the substance's identity does not change, and there is no loss or gain of matter. This illustrates the principle of conservation of mass, which states that mass cannot be created or destroyed in a closed system. Hence, when a substance undergoes a physical change, such as melting or freezing, the total mass of the system remains the same.