Which physical process is primarily responsible for breaking hydrogen bonds between water molecules as ice melts?

• A. Exposure to ultraviolet light
• B. Addition of salt to the ice
• C. Increase in atmospheric pressure
• D. Absorption of thermal energy (heat)

Answer: (D)

Verified step by step guidance

1. Understand that hydrogen bonds are intermolecular forces that hold water molecules together in the solid phase (ice).
2. Recognize that melting ice involves changing water from solid to liquid, which requires breaking these hydrogen bonds.
3. Identify that breaking hydrogen bonds requires energy input to overcome the attractive forces between molecules.
4. Recall that the primary source of this energy during melting is thermal energy (heat) absorbed by the ice.
5. Conclude that the physical process responsible for breaking hydrogen bonds as ice melts is the absorption of thermal energy (heat).