AP BIOLOGY

Detailed explanation-1: -As water temperature cools the molecules slow down, eventually slowing enough that hydrogen bonds can form and hold the water molecules in a crystal lattice. The molecules in the lattice are spaced farther apart than the molecules in liquid water, which makes ice less dense than liquid water (Figure 5.1.

Detailed explanation-2: -The property of cohesion describes the ability of water molecules to be attracted to other water molecules, which allows water to be a “sticky” liquid. Hydrogen bonds are attractions of electrostatic force caused by the difference in charge between slightly positive hydrogen ions and other, slightly negative ions.

Detailed explanation-3: -The hydrogen bonds between water molecules give water the ability to hold heat better than many other substances. As the temperature rises, the hydrogen bonds between water continually break and reform, allowing for the overall temperature to remain stable, although increased energy is added to the system.

Detailed explanation-4: -Water molecules are polar, so they form hydrogen bonds. This gives water unique properties, such as a relatively high boiling point, high specific heat, cohesion, adhesion and density.