Ice molecules can occur in sixteen different phases depending on pressure and temperature. The ice we come across in the biosphere mainly has hexagonal crystalline structure I_h.

Why does ice appear blue? The blue color is due to

• the scattering of light.
  
• the absorption of light.

This quiz is part of:

• Chemistry Advent Calendar,
  ChemViews Mag. 2015.
  DOI: 10.1002/chemv.201500102