the autonomic nervous system, which controls vital functions such as breathing, digestion, heart rate, and secretion of hormones. Skull The purpose of the bony skull is to protect the brain from injury. The skull is formed from 8 bones that fuse together along suture lines. These bones include the
Density is a measurement of how solid something is. Specifically it is the mass per unit volume of a substance. If you have two objects of the exact same size (volume), the more dense object will weigh more than the less dense object. So there are two things contributing to density:
Density is mass per unit volume Density describes how much mass is in a given volume of a material. Steel has high density; it contains 7.8 grams of mass per cubic centimeter. Aluminum, as you well might predict, has a lower density; a one-centimeter cube has a mass of only 2.7 grams. The density of water and air Liquids and gases are matter and have density. The density of water is about one gram per cubic centimeter . The density of air is lower, of course â much lower. The air in your classroom has a density of about 0.001 grams per cubic centimeter.