Final answer:
Flammability is a chemical property because it requires a change in the substance's composition, whereas density is a physical property as it can be measured without changing the substance. Gas meters should be protected from all hazards including fire, water, and physical damage. The correct option is 4) All of the above
Step-by-step explanation:
Understanding the difference between chemical and physical properties of matter is fundamental in chemistry, allowing us to predict how substances will behave in different situations. A chemical property is an attribute that can only be observed by changing the chemical identity of a substance, typically through a chemical reaction. Examples include reactivity with other chemicals, toxicity, and flammability.
In contrast, a physical property is an aspect of matter that can be observed or measured without changing it into another substance. This includes attributes like melting point, boiling point, and density. When discussing properties such as corrosiveness and pH (acidity), they can also be considered chemical properties, as they involve a substance's ability to react chemically with other materials.
To answer the question from Exercise 1.4.1B, flammability is a chemical property since it describes a substance's ability to burn or ignite, causing it to change its composition. For Exercise 1.4.1A, density is a physical property because it can be measured without changing the substance's chemical makeup. Gas meters, as mentioned in a different context, should be protected against all hazards including fire, water damage, and physical damage, meaning the answer to the student's question would be '4) All of the above'.