Atoms_Molecules_and_Ions - The lecture “Atoms. Molecules,...

The lecture “Atoms. Molecules, and Ions” begins by exploring the history of the discovery of the
atomic world. Greeks were the first to attempt a theory as to why chemical changes occur.
There are three important chemical laws: Law of conservation (Lavoisier), Law of definite
proportion (Proust), and Law of multiple proportion (Dalton). This leads us into the topic of
Dalton’s Atomic Theory. There are numerous principles when it comes to this theory. For
example, each element that exists is made up of tiny particles called atoms. In addition,
chemical compounds are made when the atoms of the elements are combined. Also, chemical
reactions involve the reorganization of the atoms. There are other important scientists who
came up with discoveries as well such as Gay-Lusac and Avogadro. Gay-Lusac measured the
volumes of gases that reacted with each other, and Avogadro found that at the same time, T
and P equal volumes of different gases contain the same number of particles. J.J. Thompson
postulated the experience of electrons by using this device called the cathode ray tubes. Ernest