Events
Democritus
Credited for the creation of atomic theoryAristotle
Didn't believe in atomic theory and taught so
otherwise. He believed that everything was
created from the four elements; fire, earth,
water, and airJohn Dalton
Credited for improving the atomic theoryJames Chadwick
Credited for the discovery of neutronsJ.J. Thompson
Credited for the discovery of electronsRobert Andrews Millikan
Credited for the discovery of electron chargeErnest Rutherford
Credited for the discovery of protonsCathode Ray
Over the course of three experiments J. J. Thomson discovered the existence of electrons. He did this using a cathode ray tube, which is a
vacuum-sealed tube with a cathode and anode on one end that creates a beam of electrons travelling towards the other end of the tubeGold Foil Experiment
Physicist Ernest Rutherford established the nuclear theory of the atom with his gold-foil experiment. When he shot a beam of alpha
particles at a sheet of gold foil, a few of the particles were deflected. He concluded that a tiny, dense nucleus was causing the deflections.Oil Drop Experiment
The oil drop experiment was performed by Robert A. Millikan and Harvey Fletcher to measure the elementary electric charge (the
charge of the electron). The experiment entailed observing tiny electrically charged droplets of oil located between two parallel metal surfaces, forming the plates of a capacitor.Plum Pudding Model
The Plum Pudding Model is a model of atomic structure proposed by J.J. Thomson in the late 19th century. Thomson had discovered that
atoms are composite objects, made of pieces with positive and negative charge, and that the negatively charged electrons within the atom were very small compared to the entire atom.Rutherford Model
The Rutherford model is a model of the atom devised by Ernest Rutherford. Rutherford directed the famous Geiger–Marsden
experiment which suggested, upon Rutherford's 1911 analysis, that J. J. Thomson's plum pudding model of the atom was incorrect.Cell Nucleus-Anton Leewenhoek
In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells.
Comments