Answer: Rocket fuel (cryogenic propellant).
- A Rocket fuel (cryogenic propellant)
- B A substitute for drinking water in emergency supplies
- C A high-temperature lubricant for industrial machinery
- D A solid electrode material in galvanic cells
Correct answer: A. Rocket fuel (cryogenic propellant)
Explanation: Liquid H<sub>2</sub> is used as cryogenic rocket fuel; it has the highest specific impulse of any chemical propellant.
Each water molecule's O-H bonds (covalent, solid) can hydrogen-bond (dashed) to neighbouring molecules, forming an extended network responsible for water's unusually high boiling point and density anomaly.
Concept context
The simplest and most abundant element in the universe. Study its unique position in the periodic table, isotopes (protium, deuterium, tritium), properties of water and hydrogen peroxide, and industrial uses.