Final answer:
A statement could depict a physical property if it is a measurable characteristic that doesn't alter the substance's identity, or a chemical property if it involves reactivity and production of new substances. Similarly, a change is physical if only the state or form of the matter changes and chemical if the matter's identity itself is transformed through a reaction.
Step-by-step explanation:
When determining whether a statement represents a physical property or a chemical property, it is essential to understand the difference between the two. Physical properties can be observed or measured without changing the substance's chemical identity, such as color, density, and melting point. On the other hand, chemical properties are characteristics that describe how a substance reacts with other substances to form new compounds, such as reactivity and flammability.
Given statements from a student's schoolwork question:
- A pile of leaves slowly rots in the backyard -- this is a chemical property, as rotting involves the decomposition of the leaves into other substances.
- In the presence of oxygen, hydrogen can interact to make water -- this also illustrates a chemical property, specifically reactivity with oxygen to form water.
- Gold can be stretched into very thin wires -- this highlights a physical property, malleability, which does not change the chemical identity of the gold.
Regarding whether a situation represents a physical change or a chemical change:
- Water boils and becomes steam -- this is a physical change, as the water's chemical composition remains unchanged, only its state changes from liquid to gas.
- Food is converted into usable form by the digestive system -- this represents a chemical change, as the food undergoes a chemical reaction resulting in new substances that the body can utilize.
- The alcohol in many thermometers freezes at about -40 degrees Fahrenheit -- this is a physical change, because the chemical composition of the alcohol does not change when it freezes.