Final answer:
Amorphous ice, unlike crystalline solids, lacks an ordered internal structure and therefore may exist in a continuum of densities between 0.95 and 1.25 g/cm³. The variations in amorphous ice densities are due to different molecular packing, enabling a spectrum of amorphous phases.
Step-by-step explanation:
Amorphous ice is a form of water that exists as a solid but lacks the ordered crystal structure typical of other solid phases like crystalline ice. When liquids like water are cooled, they can form crystalline solids, where particles align into a repeating arrangement. Conversely, if the liquid freezes before the molecules can order themselves, it forms an amorphous solid, where the particles are randomly arranged.
Concerning amorphous ice, it comes in different densities, known as low, medium, high, and very high density. These densities can indeed be seen as a spectrum since amorphous solids do not have a sharp melting point and lack a regular external structure.
As such, it is plausible that amorphous ice could have densities within a range between 0.95 and 1.25 g/cm3. These variable densities are the result of the different ways the molecules are packed together, and since there is no strict repeating pattern, intermediate densities may exist.
It's important to note that the behavior of water is unique due to its hydrogen bonding. Water reaches its maximum density at about 4°C, and unlike most substances, solid water (ice) is less dense than liquid water. This is why ice floats on water and has implications for the formation of different ice phases.