Which of the following is the primary basis for classifying matter in chemistry?

• A. By its color and odor
• B. By its mass and volume
• C. By its physical state and composition (element, compound, mixture)
• D. By its temperature and pressure

Answer: (C)

Verified step by step guidance

1. Understand that in chemistry, matter is classified based on intrinsic properties that define its nature and behavior rather than arbitrary or variable characteristics like color or odor.
2. Recognize that mass and volume are physical quantities used to measure matter but do not serve as the primary classification criteria because they do not describe the type or nature of the matter itself.
3. Recall that temperature and pressure are conditions that can affect matter but are not used to classify matter itself; instead, they influence the state or behavior of matter.
4. Focus on the physical state (solid, liquid, gas) and composition (whether the matter is an element, compound, or mixture) because these characteristics fundamentally describe what the matter is and how it can be categorized.
5. Conclude that the primary basis for classifying matter in chemistry is by its physical state and composition, as this classification reflects the essential chemical and physical nature of the substance.