The History of the Atom 5: The Modern Theory investigates the development of modern atomic theory. Greek philosophers Leucippus and Democritus first developed the concept of the atom in the 5th century B.C.E.
Therefore, based on the concepts of the continental drift and other developing ideas at the time, a general theory was developed, which is now known as the plate tectonics. Plate Tectonics. Plate tectonics is the theory explaining the motion of the outer crust or the lithosphere of earth. Lithosphere is divided into tectonics plates. Two main types of tectonics plates are the oceanic crust and continental crust. Oceanic crust is mainly composed of Silicon and magnesium, hence called SIMA.
5. Plate tectonic theory builds on the continental drift hypothesis and the theory of seafloor spreading. As such, it is a unifying theory of geology. Explain why it is a unifying theory. ANSWER: Plate tectonic theory ties together observations used to support continental drift with the driving mechanism from seafloor spreading and with other seemingly unrelated data and observations, such as paloemagnetism and the occurrence of earthquakes and volcanism.