Which of the following is a chemical property of hydrogen?

• A. It has a density lower than air.
• B. It is tasteless.
• C. It is colorless at room temperature.
• D. It reacts explosively with oxygen to form water.

Answer: (D)

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. Review each option and classify it as a physical or chemical property: Density, taste, and color are physical properties because they describe observable characteristics without changing the substance.
3. Identify the option that involves a chemical change: The statement 'It reacts explosively with oxygen to form water' describes a chemical reaction where hydrogen combines with oxygen to form a new substance, water.
4. Recognize that this reaction involves breaking and forming chemical bonds, which is the hallmark of a chemical property.
5. Conclude that the correct chemical property of hydrogen is its ability to react explosively with oxygen to form water.