Which of the following is a chemical property of sodium?

• A. It has a melting point of 98 °C.
• B. It conducts electricity in solid form.
• C. It reacts vigorously with water to produce hydrogen gas.
• D. It is a soft, silvery metal.

Answer: (C)

Verified step by step guidance

1. Understand the difference between physical and chemical properties: Physical properties can be observed or measured without changing the substance's identity, while chemical properties describe how a substance interacts with other substances, leading to a change in its chemical composition.
2. Analyze each option to determine if it describes a physical or chemical property:
3. - Melting point (98 °C) is a physical property because it describes a phase change without altering the chemical identity of sodium.
4. - Conducting electricity in solid form is a physical property related to the movement of electrons within the metal structure, not a chemical change.
5. - Reacting vigorously with water to produce hydrogen gas is a chemical property because it involves a chemical reaction that changes sodium into new substances (sodium hydroxide and hydrogen gas).