Which of the following best describes how temperature and salinity affect the density of water?

• A. Increasing temperature decreases density, while increasing salinity increases density.
• B. Both increasing temperature and increasing salinity decrease density.
• C. Both increasing temperature and increasing salinity increase density.
• D. Increasing temperature increases density, while increasing salinity decreases density.

Answer: (A)

Verified step by step guidance

1. Understand that the density of water depends on both temperature and salinity, which affect how closely water molecules are packed together.
2. Recall that increasing temperature generally causes water molecules to move faster and spread apart, which decreases the density of water.
3. Recognize that increasing salinity means adding dissolved salts to water, which increases the mass of the water without significantly increasing its volume, thus increasing its density.
4. Combine these effects: higher temperature leads to lower density, while higher salinity leads to higher density.
5. Use this understanding to evaluate the given options and identify the statement that correctly describes these relationships.