The study of chemistry began as the combination of ancient technologies, such as metallurgy and soap making, the medieval attempts to make gold, and efforts to improve medicine. Antoine Lavoisier is considered to be the father of modern chemistry because of his distinction between elements and compounds and his insistance that chemical reactions are quantitative. John Dalton's development of the atomic theory caused chemistry to evolve quickly. An atom is the smallest piece of an element that has the element's chemical properties. Even living systems are made up of fundamental particles and, as studied in biology , biophysics and biochemistry, they follow the same types of laws as the simpler particles traditionally studied by a physicist.
Atoms join or 'bond' together to form molecules by sharing their electrons.
Chemical bonding is essentially the interaction of electrons from one atom with the electrons of another atom. They might join together with others of the same kind. Oxygen molecules contain two identical oxygen atoms. Water molecules each contain two hydrogen atoms and one oxygen atom. When the atoms are of different elements, the substance formed is called a compound .