Question

The bonds between neighboring water molecules expand when water freezes into solid ice from a liquid. Part 1: Describe the relationship between the structure of water and its density. Part 2: Explain the impact ice has on a population of lake grass, Carex lacustris, that goes dormant but does not die in a frozen lake in winter.

Answer 1

Water forms a structured, lattice-like ice that is less dense than liquid water, allowing it to float and insulate the water below. This feature creates a protective barrier that helps Carex lacustris survive in a dormant state beneath the ice-covered lake surface during winter.

Step-by-step explanation:

In response to Part 1 of the question, the relationship between the structure of water and its density is that a water molecule's unique shape, polarity, and ability to form hydrogen bonds lead to an open, lattice-like structure when water freezes. This structure is less dense than the liquid water because the molecules are farther apart; hence, ice floats on the surface rather than sinking.

Regarding Part 2, the impact that ice has on a population of lake grass, such as Carex lacustris, is crucial in a frozen lake during winter. The formation of ice on the surface acts as an insulating barrier, maintaining the water underneath at a liquid state and protecting the dormant lake grass from freezing temperatures. Without this insulating layer, if the Carex lacustris were to freeze in a solid block of ice, it could not survive.

Answer 2

The density of water is influenced by its structure, with ice being less dense than liquid water. Ice forms an insulating barrier on the surface of a frozen lake, protecting plant life, such as Carex lacustris, from freezing.

Step-by-step explanation:

Part 1:

The density of water is influenced by its structure. The hydrogen bonds between water molecules keep them relatively close together, resulting in a high density in the liquid phase. However, when water freezes into ice, the hydrogen bonds lock the molecules into a lattice-like structure, causing them to spread apart and increase the volume occupied by the same amount of water molecules. This expansion leads to a decrease in density, making ice less dense than liquid water.

Part 2:

Ice has a significant impact on populations of lake grass, such as Carex lacustris, that go dormant but do not die in a frozen lake during winter. The layer of ice that forms on the surface of the lake acts as an insulating barrier, protecting the plants beneath from freezing. Without this ice layer, the plants would freeze in a block of ice, damaging their delicate structures and potentially causing death. Therefore, ice allows lake grass and other organisms to survive in freezing temperatures.