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.
THE THEORY OF CONTINENTAL DRIFT. The drifting of tectonic plates is an on-going process that has changed the configuration of the continents since their formation in Archean time. This hypothesis first proposed in 1912 by Alfred Wegener, a German Meteorologist, was not widely accepted until after 1960.Wegener's evidence for continental drift includes:he drifting of tectonic plates is an on-going process that has changed the configuration of the continents since their formation in Archean time. This hypothesis first proposed in 1912 by Alfred Wegener, a German Meteorologist, was not widely accepted until after 1960. Wegener's evidence for continental drift includes: