Correct Answer:
C. Hydrogen Bond
The correct answer is Hydrogen Bond. The attractive force that holds one water molecule to another is the hydrogen bond. This intermolecular bond is responsible for water's unique properties, including high surface tension, boiling point, and its ability to dissolve many substances.
Hydrogen Bonding in Water
- How It Forms: In a water molecule (H₂O), the oxygen atom is highly electronegative, pulling electrons away from the hydrogen atoms. This creates a partial negative charge on the oxygen and a partial positive charge on each hydrogen. The positively charged hydrogen of one molecule is attracted to the lone pair electrons of the oxygen on a neighboring molecule — this attraction is the hydrogen bond.
- Intermolecular, Not Intramolecular: The bonds within a single water molecule (O–H) are polar covalent bonds, where electrons are shared. The question asks about bonding between molecules, which is the hydrogen bond.
- Why Not Other Bonds?: Ionic bonds involve complete transfer of electrons between metal and non-metal atoms, not between neutral water molecules. Metallic bonds occur among metal atoms. The only accurate description of intermolecular bonding in water is hydrogen bonding.
- Significance of Hydrogen Bonds: These relatively weak bonds are collectively strong enough to give water a high specific heat, capillary action in plants, and ice's lower density than liquid water — all essential for life.
Therefore, the bonding between water molecules is a hydrogen bond.