Geologic time is divided into four large segments called Eons: Hadean, Archean, Proterozoic, and Phanerozoic. The Phanerozoic Eon isdivided into Eras: Paleozoic, Mesozoic, and Cenozoic. The divisions among Eras reflect major changes in the fossil record, including the extinction and appearance of new life forms.
The geological time scale is divided on the basis of the information obtained from the<u> fossil evidences</u> and the rock specimens. The fossils of oldest organisms found on earth have depicted that the organisms were much simpler and with the increasing time, became more complex and structurally developed.
This classification was made by orderly arranging the main events that have taken place in the past, since the time of formation of the earth, till the present. The first unicellular life exited on earth about 3.5 billion years ago, and from that moment, continuous evolution has taken place depending upon the various geological factors that led to the development of more specific and well structured multi-cellular organisms by about 600-700 million years back.
Caffeine has the following percent composition: carbon 49.48%, hydrogen 5.19%, oxygen 16.48% and nitrogen 28.85%. Its molecular weight is 194.19 g/mol.
