What is the chemical formula for water?

• A. H₂O
• B. CO₂
• C. NaCl
• D. C₆H₁₂O₆

Answer: (A)

The chemical formula for water is H₂O, which indicates that each molecule of water is composed of two hydrogen atoms bonded to one oxygen atom. This simple yet essential formula represents the most abundant compound on Earth, playing a critical role in various biological, chemical, and physical processes. For instance, water is vital for life, as it serves as a solvent in biological reactions, regulates temperature, and facilitates nutrient transport. Understanding the molecular composition of water is fundamental in numerous scientific fields, including chemistry, biology, and environmental science.

In contrast, the other options represent different compounds: CO₂ is carbon dioxide, essential for life as a part of the carbon cycle but not related to water; NaCl is sodium chloride, commonly known as salt; and C₆H₁₂O₆ is glucose, a simple sugar vital for energy in living organisms. Each of these compounds has distinct chemical properties and functions that differ significantly from those of water.