Question

question 30 of 41
if the solid form of most molecules is heavier than the liquid form, why does ice float?
○ the crystalline structure of ice is less dense than liquid water.
○ the arrangement of frozen water molecules prevents them from interacting with water molecules in liquid form
○ the crystalline structure of ice is denser than liquid water.
○ a water molecule is larger in the liquid state than in the solid state.

which examples illustrate how the property of ice floating on water supports life on earth?
□ ice provides arctic and antarctic animals with a land habitat.
□ ice affects aquatic habitats at all depths equally.
□ the amount of usable area in the arctic and antarctic regions is reduced during winter.
□ aquatic animals can survive when the surface of water freezes.

Explanation:

For the first question: Floating depends on density—less dense substances float. Ice’s hexagonal crystal structure (from hydrogen bonding) spaces molecules more than liquid water, making ice less dense.
For the second question: Floating ice creates habitats for polar animals. It also insulates water below, keeping it liquid so aquatic life survives freezing conditions. The other options are incorrect (ice doesn’t affect all depths equally; usable area isn’t reduced in a way that supports life).

Answer:

The crystalline structure of ice is less dense than liquid water.
Ice provides arctic and antarctic animals with a land habitat.
Aquatic animals can survive when the surface of water freezes.