Which statement best describes the relationship between temperature and the density of a substance?

• A. As temperature increases, the density of a substance generally decreases.
• B. As temperature increases, the density of a substance generally increases.
• C. Temperature has no effect on the density of a substance.
• D. As temperature increases, the density of a substance remains constant.

Answer: (A)

Verified step by step guidance

1. Recall the definition of density, which is the mass of a substance divided by its volume, expressed as \(\text{density} = \frac{\text{mass}}{\text{volume}}\).
2. Understand that when temperature increases, most substances expand, meaning their volume increases while their mass remains constant.
3. Since the volume increases and mass stays the same, the density, which depends inversely on volume, will decrease.
4. Therefore, the relationship between temperature and density is generally inverse: as temperature goes up, density goes down.
5. This explains why the correct statement is: 'As temperature increases, the density of a substance generally decreases.'