Final answer:
The student's question relates to identifying a physical change among given options. The correct answer is A, going from liquid to solid, as it is the only listed process that does not alter the substance's chemical composition.
Step-by-step explanation:
The question asks to identify which of the following is a physical change:
- Going from liquid to solid
- Putting baking soda and vinegar together
- Burning a paper
- Cooking
A physical change is a type of change in which the form of matter is altered, but one substance is not transformed into another, whereas a chemical change results in the transformation of one substance into another substance with different properties.
Option A, going from liquid to solid, is a physical change. This is because the substance itself doesn't change its chemical composition or identity; it only changes its state, from liquid to solid. An example will be water freezing into ice.
Option B is not a physical change; when baking soda and vinegar are mixed, they react chemically to produce new substances, indicating a chemical change. Option C, burning a paper, is also a chemical change as the paper is transformed into ash and other gases. Option D, cooking, broadly involves chemical changes though it can also encompass some physical changes; for example, cooking an egg involves the denaturation of proteins, which is a chemical change.