To determine which of these is a chemical property of aluminum, we first need to understand the distinction between physical properties and chemical properties.
1. Physical Properties: These are characteristics that can be observed or measured without changing the substance's chemical identity. Examples include:
- Density
- Color
- Hardness or softness
2. Chemical Properties: These are characteristics that describe how a substance interacts with other substances, leading to a change in its chemical structure. An example would be reactivity with other chemicals.
Now, let's examine each statement to see if it fits the definition of a physical or chemical property:
1. "Aluminum has a density of [tex]$2.70 g \cdot cm^{-3}$[/tex]."
- Density is a measure of mass per unit volume and does not involve changing the substance’s chemical structure. Therefore, this is a physical property.
2. "Aluminum is silvery white in color."
- Color is a characteristic that can be observed without altering the substance itself, making it a physical property.
3. "Aluminum is highly reactive."
- Reactivity describes how a substance undergoes a chemical change when it comes into contact with other substances. Since it involves a change in chemical composition, this is a chemical property.
4. "Aluminum is a soft metal."
- The softness of a metal is a physical trait because it describes a physical characteristic that does not involve any change in chemical identity. Hence, this is a physical property.
Considering all the definitions and explanations, we conclude that the chemical property of aluminum listed here is:
"Aluminum is highly reactive."
Thus, the answer is the statement:
Aluminum is highly reactive.
