When water freezes, water molecules form a crystalline structure maintained by hydrogen bonding. Solid water, or ice, is less dense than liquid water. Ice is less dense than water because the orientation of hydrogen bonds causes molecules to push farther apart, which lowers the density.
Brain death: is the legal definition of death. It is the complete and irreversible stop of all brain functions. This means that as a result of severe aggression or severe brain injury, the blood that comes from the body and supplies the brain is blocked and the brain dies.
Agonal phase: occurs with the realization of the preceding events when life is about to break free of the protoplasm, because the protoplasm cannot sustain it for long.
Clinical death: is defined by the cessation of electrical activity in the brain, resulting in irreversible and total loss of neurological activity in the brain and brainstem. When doctors officially declare a person's clinical death, it means there is no cure or return to recovery.
Mortality: It is the condition of being mortal, therefore, of being susceptible to death. However, the term mortality is in most cases related to the statistical studies applied on populations. So mortality appears as a number that seeks to establish the number of deaths over a given population.
