Attractions between water molecules are called

• A. Ionic bonds
• B. Metallic bonds
• C. Covalent bonds
• D. Hydrogen bonds

Answer: (D)

Water molecules attract each other mainly through hydrogen bonds. Water is a polar molecule: oxygen is more electronegative than hydrogen, so the shared electrons in the O–H bonds spend more time near the oxygen, giving it a partial negative charge and leaving the hydrogens with a partial positive charge. A hydrogen from one water molecule is attracted to the lone pairs on the oxygen of a neighboring water molecule, forming a hydrogen bond. These bonds are weaker than covalent bonds but strong enough to hold water molecules together in the liquid, giving water its cohesion, high surface tension, and contributes to ice being less dense than liquid water.

These other bond types describe different situations: ionic bonds form between oppositely charged ions, metallic bonds occur in metals where electrons are shared in a sea of electrons, and covalent bonds are the bonds that keep atoms together within a single molecule.