Final answer:
Water is formed through a chemical reaction between hydrogen and oxygen gases, leading to a substance with unique properties due to its molecular structure and ability to form hydrogen bonds.
Therefore Option (a) is correct
Step-by-step explanation:
Water is composed of hydrogen and oxygen through a process called chemical combination, particularly a type of reaction called a combustion reaction. Therefore, option A is correct - water forms through a chemical reaction between hydrogen and oxygen. Hydrogen and oxygen gases react in the presence of energy to form water, following the equation 2H2(g) + O2(g) -> 2H2O(l). This transformation leads to a substance (water) with entirely different properties than its constituent elements.
Water derives its unique properties from the nature of its molecular structure and its ability to form hydrogen bonds. For example, unlike hydrogen and oxygen gases, water is a liquid at room temperature, has high heat capacity, and is a good solvent for many substances, among other properties. These properties differ significantly from those of the gaseous elements hydrogen and oxygen because of the nature of chemical bonds and the resultant change in physical and chemical properties after a chemical reaction.
Learn more about Chemical Properties of Water