Butter melt when you heat it in a pan on the stove. Is this a chemical change or physical change?
The correct answer and explanation is:
Melting butter is a physical change.
A physical change occurs when a substance undergoes a transformation in its state or appearance, but its chemical composition remains the same. In the case of butter, when it is heated in a pan, it changes from a solid to a liquid due to the heat energy causing the molecules to move faster and break the bonds holding them together in the solid state. However, the chemical structure of the butter does not change. The fat molecules in the butter, primarily made up of triglycerides, remain the same before and after melting.
Physical changes can usually be reversed. If you were to cool the melted butter, it would solidify again. This reversibility is a key characteristic of physical changes. In contrast, a chemical change would involve the formation of new substances with different chemical structures, and this process is typically irreversible. For example, burning butter would involve a chemical change because it would break down into new compounds like carbon dioxide and water.
In summary, the melting of butter is a physical change because it involves a change in the state of matter (from solid to liquid) without altering the butter’s chemical composition.