Bones consist of living cells embedded in a mineralized organic matrix. This matrix consists of organic components, mainly type I collagen – "organic" referring to materials produced as a result of the human body – and inorganic components, primarily hydroxyapatite and other salts of calcium and phosphate.
atoms are the smallest units of matter that still retain the fundamental chemical properties of an element. much of the study of chemistry, however, involves looking at what happens when atoms combine with other atoms to form compounds. a compound is a distinct group of atoms held together by chemical bonds. just as the structure of the atom is held together by the electrostatic attraction between the positively charged nucleus and the negatively charged electrons surrounding it, the stability within chemical bonds is also due to electrostatic attractions. to illustrate further, consider the two major types of chemical bonds: covalent bonds and ionic bonds. in covalent bonds, two atoms share pairs of electrons, while in ionic bonds, electrons are fully transferred between two atoms so that ions are formed. let’s consider both types of bonds in detail.
covalent bonds and molecules
a covalent bond is formed when two atoms share electron pairs. in a covalent bond, the stability of the bond comes from the shared electrostatic attraction between the two positively charged atomic nuclei and the shared, negatively charged electrons between them.
a single, neutral hydrogen atom is shown on the left; a molecule of hydrogen, h2, is shown on the right.