All matter has physical and chemical properties. which of these describes a chemical property? a. boiling point b. flexibility c. electrical conductivity d. reactivity with water
The Correct Answer and Explanation is:
Correct Answer: d. reactivity with water
Explanation:
All matter exhibits both physical and chemical properties. Physical properties are characteristics that can be observed or measured without changing the substance’s identity. Examples of physical properties include boiling point, melting point, color, mass, and flexibility. These traits can be detected through the senses or measured with tools, and they do not alter the composition of the substance when observed.
Chemical properties, on the other hand, describe how a substance interacts with other substances and the kinds of changes it can undergo to form new substances. When a chemical property is observed, the substance’s identity is changed. For example, flammability, oxidation, and reactivity with acids or water are all chemical properties because they involve a chemical reaction and the formation of a new substance.
Among the given options:
- Boiling point is a physical property because it is the temperature at which a substance changes from liquid to gas. This process involves a change in state but not a change in the substance’s chemical identity.
- Flexibility is also a physical property. It refers to the ability of a material to bend without breaking. This does not involve any chemical transformation.
- Electrical conductivity is the ability of a substance to conduct electricity. It is classified as a physical property because it involves the movement of electrons but does not change the chemical composition of the substance.
- Reactivity with water is a chemical property. When a substance reacts with water, a chemical change occurs, resulting in the formation of one or more new substances. For example, sodium reacts vigorously with water to form sodium hydroxide and hydrogen gas, which demonstrates a clear chemical change.
Thus, reactivity with water is the correct choice as it reflects a chemical property.
