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.
While conducting research at Cambridge University, James Chadwick worked with Ernest Rutherford. Rutherford engrained his name in history when he discovered the proton. With more research, he â as well as other researchers â determined that it was not the only particle that made up the nucleus. Rutherford hired Chadwick in 1921, where he focused his research on radioactivity.