Final answer:
Both bleaching clothes and making paper from wood are processes that involve chemical changes, and they both conserve mass in accordance with the Law of Conservation of Mass.
Step-by-step explanation:
The question is asking to identify what two changes, bleaching clothes and making paper from wood, have in common. To determine this, we need to look at the nature of both processes.
Bleaching clothes typically involves breaking down stains or the original dye color on the fabric through chemical reactions, which illustrates a chemical change.
Making paper from wood requires breaking down the cellulose fibers of wood, often involving chemical reactions with substances like sodium hydroxide and sulphuric acid, leading to the formation of a pulp and eventually paper. This transformation also constitutes a chemical change.
Considering the options provided, we can assert:
- a. Both are chemical changes.
- c. Both conserve mass. This principle is a fundamental aspect of chemical changes, as the Law of Conservation of Mass states that mass is neither created nor destroyed in chemical reactions.
These commonalities are based on fundamental principles of chemistry, and the transformations that occur are indeed lasting and create new substances, different from what we started with.