In the process of attempting to characterize a substance, a chemist makes the following observations: The substance is a silvery white, lustrous metal. It melts at 649 °C and boils at 1105 °C. Its density at 20 °C is 1.738 g/cm³. The substance burns in air, producing an intense white light. It reacts with chlorine to give a brittle white solid. The substance can be pounded into thin sheets or drawn into wires. It is a good conductor of electricity. Which of these characteristics are physical properties, and which are chemical properties?

Key Concepts

Physical Properties

Physical properties are characteristics of a substance that can be observed or measured without changing its chemical identity. Examples include color, melting point, boiling point, density, and conductivity. These properties describe the state and appearance of the substance and can often be determined through physical changes, such as melting or boiling.

Chemical Properties

Chemical properties describe how a substance interacts with other substances, leading to a change in its chemical composition. These properties are observed during chemical reactions and include reactivity with air, the ability to burn, and reactions with other elements, such as chlorine. Understanding chemical properties is essential for predicting how a substance will behave in different chemical environments.

Distinguishing Between Physical and Chemical Properties

Distinguishing between physical and chemical properties is crucial for characterizing substances accurately. Physical properties can be measured without altering the substance, while chemical properties require a reaction that changes the substance's identity. This distinction helps chemists understand the behavior of materials and predict their reactions in various conditions.