1 Blood Cells: The most common types of blood cells are:  red blood cells (erythrocytes). The main function of red blood cells is to collect oxygen in the lungs and deliver it through the blood to the body tissues. Gas exchange is carried out by simple diffusion.
Rutherford and Bohr describe atomic structure1913. Photo: Niels Bohr's research notes for his new atomic theory. In 1911, Niels Bohr earned his PhD in Denmark with a dissertation on the electron theory of metals. Right afterwards, he went to England to study with J.J. Thomson, who had discovered the electron in 1897.
(1766-1844). English meteorologist and chemist John Dalton was a pioneer in the development of modern atomic theory. Because of his scientific contributions, he is at times considered both the father of chemistry and the father of meteorology..