Which of the following statements about air is correct?

• A. Air is matter because it has mass and occupies space.
• B. Air is not matter because it is invisible.
• C. Air is a pure substance.
• D. Air is energy, not matter.

Answer: (A)

Verified step by step guidance

1. Recall the definition of matter: Matter is anything that has mass and occupies space.
2. Consider air: Although it is invisible, air has mass and takes up space, which means it fits the definition of matter.
3. Evaluate the other options: Air is not a pure substance because it is a mixture of gases (mainly nitrogen, oxygen, and small amounts of other gases).
4. Understand that air is not energy; energy is a property or ability to do work, while air is a physical substance.
5. Conclude that the correct statement is that air is matter because it has mass and occupies space.