<(1900--1915).

Robert Millikin





1868-1953

**Discovery:** 1901 Robert Millikan was born in 1868 in the town of Morrison Illonois, he got his mastership in physics in 1893 and became a professor at the University of Chicago in 1910 and remained there until 1921. Robert Millikan made numerous discoveries including some in the fields of electricity optics and molecular physics. Millikan put an end to all opposition to the atomic and kinetic theories of matter, and also in the early 1920's Millikan worked with the hot spark spectroscopy thus extending the ultraviolet spectrum downwards beyond what was commonly known. Robert Millikan's greatest ealrier discovery involved the detection and masurement of the effect of an individual subatomic particle. He did this by using the experiment wich is known as the "oil drop experiment". In this experiment Millikan applied a charge to falling drops of oil and then he created an electric field between the plates thus creating a magnetic field and suspending the drops of oil, which were falling at terminal velocity due to air resistance, in mid-air.
 * Nobel Prize Recipient**: 1923


 * Marie Curie **
 * 1867-1934**

**Discovery:**1903 **Nobel Prize Recipient:** 1903, 1911 Marie Curie was born in Warsaw on November 7, 1867. She was educated by the local schools and by her father in science. While working with her husband doing research in their very poor and difficult condition laboratory they researched radioactivity. Henri Becquerel inspired this couple due to his discovery of radioactivity in 1896. They discovered isolation of polonium, which was named after the country of Marie’s birth, and radium. Marie Curie developed the methods for separating radium’s from radioactivity residues in sufficient quantities to allow for its characterization and the careful study of its therapeutic properties.


 * __ Ernest Rutherford __**



1871-1937  Discovery: 1911 Nobel Prize Recipient: 1908 Ernest Ruherford was born in Brightwater, New Zealand. He was a chemist and a physicist who became known as the father of Nuclear Physics. Ernesst studied at Canterbery College, University of New Zealand, and also at the University of Cambridge in England. At one point Ernest held the record for the distance over which electromagnetic waves could be detected. Ernest Rutherford made very important discoveries in the field of radiation. He dicovered and named the three types of radiation alpha,beta, and gamma. Ernest also dicovered the half-life of radioactive materials. Rutherford's discoveries were pivotal in the progress of the Manhattan Project which was the developing of the Nuclear Bomb. Rutherford continued his research on the properties of the radium emanation and of the alpha rays and a method of detecting a single alpha particle and counting the number emitted from radium was devised. In 1910, his investigations into the scattering of alpha rays and the nature of the inner structure of the atom which caused such scattering led to the postulation of his concept of the "nucleus". According to Rutherford the entirty of the the positive charge of the atom was cncentrated at the centre of the atom. He found this out by using his gold foil experiment wwhich he fired radioactive ions at a piece of gold foil and watched them be deflected in different ways.

Neils Bohr



1885-1965 Discovery: 1913 Nobel Prize Recipient: 1922 Bohr made numerous contributions to our understanding of the structure of properties of atoms. He won the 1922 Nobel Prize for physics, chiefly for his work on atomic structure. While studying under Ernest Rutherford in his early years Bohr, in 1913, published a theory about the structure of the atom based on an earlier theory of Rutherford's. Rutherford had shown that the atom consisted of a positively charged nucleus, with negatively charged electrons in orbit around it. Bohr expanded upon this theory by proposing that electrons travel in orbits around the nucleus and stay on those paths.