The brain stem connects the brain with the spinal cord. It controls hunger and thirst and some of the most basic body functions, such as body temperature, blood pressure, and breathing. The brain is protected by the bones of the skull and by a covering of three thin membranes called meninges.
When they become a solid, as in a solid the particles are packed tightly together and have little space between them, thus at solid state , particles are more ordered.
