Atomic Timeline

By: Abby Koons

Main

Joseph Proust

1794

He was born September 26, 1754 and died July 5, 1826. He came up with the Law of Definite Proportions. The law states "A compound is composed of exact proportions of elements by mass regardless of how the compound was created". https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcQliQ2-q8SL2lkhvV4d7eV4WGcdJ-iGgv0RmhzjVZ3TTL-VmBg2hw https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSAMV6jA3G89T-UwgdugmaMZVdQEq8JEvZro3hL75P4mv-jlAmazg

John Dalton

1803

He was born September 6, 1766 and died July 27, 1844. John proposed the Atomic Theory as " All matter was composed of small indivisible particles named atoms atoms of a given element posses unique characteristics and weight, and there are three types of atoms called simple, compound, and complex". https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTsZBu8sCnbvYrCzBrhjn84sBv5nYzTlTuPldDXF1ObDR8EFXzw https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcReHdAoAhakySMoyQxBZcwBzzznKlx4iKL0I73LT7dWQfCIFjNOnQ

Amedeo Avogado

1811

He was born August 9, 1776 and died July 9, 1856. He came up with his own molecular theory. He said " Equal volumes of gases contain equal numbers molecules at the same temperature and pressure" and "gas molecules can divide during chemical reactions" . https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcRxnbzv_JkcbIHQv7WVQjqnfmN4VuF3jCmaZvnEyMgw0f9eRBil https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcQ9B8qNVOrYdsyJOm-Tr3rFdYQsUMz7z4kK6KJH5maHh9Jrt6P0

Dimitri Mendeleev

1869

Mendeleev was born February 8, 1834 and died February 2, 1907. At the time he knew nothing about electrons but he arranged the elements on the periodic table. https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRWYsqH-QMfffDwuIZGGPQ0Ru8_Nb_861vZlqcfJRqIg5DLcS06 https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcQ11MWwec1NhNy2ftJT8ihynM94wmcUohw0jLK8a5hKvvf_d_xlcw

JJ Thomson

1897

He was born on December 18, 1856 and he died August 30, 1940. He did many things in science. He proposed a model of an atom, found evidence that negatively charged particles could be taken out of an atom, and he measured the ratio of mass-to-charge for an electron. https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTGSBnhLe-xODwkTbXGf2c1p-0QNCkZ8AKEmbiHJlangJ3i3obUjw https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcQkMtfZkgkHeTjwl-DDUzgSbm_OWZ68oT_Kxa2XTGpyH0iqxqCr

Marie Curie

1898

She was born November 7, 1867 and died July 4, 1934. Through her research she came up with "Radio Activity" which is the decay of Uranium and Thorium. She also discovered Polonium and Radium with help of her Husband. https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcSzX1tXn-0qzuWBMxVpMW09o4K63Rn1FH_nbx7ZfHjBVnZhmc9r https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcTAHu17ed21gjvWqczb97dgMHb8xz_hY9boADTLf21J3QG0Dz_7oQ

Ernest Rutherford

1911

Ernest was born on August 30, 1871 and died October 19, 1937. He conducted an experiment to learn about the atom and concluded that the grid of an atom has tiny cells and there is not a lot of positive charge. By doing this he discovered the atomic nucleus. https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTBEmDG_khGLyz65W657juOAWxawtLVBvJ83SR4Ks70541Hg2SZ https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcSHf-S1D7Yhv3hIYEBebnGyPrqX6CWJDVMEf5UM6zWJE3U58-y_

Niels Bohr

1922

He was born October 7, 1885 and died November 18, 1962. He proposed a "Planetary" model of an atom. He believed that electrons are able to "jump" between energy levels or orbits.
https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcQiQxsypP14ZWX2rvDA1Z_hZqUQ690EB4JlbscPXjIkdQsXXRUo https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcS2zMcZrgNJfKKxuy5okJXuXlE7v-NfcXH2z2Q3_fvoS-MZ6gAL

Hans Geiger

1928

Hans was born September 30, 1882 and died September 24, 1945. He co-invented the Geiger Counter which was a machine that counted alpha particles. https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcSjDG2OVSZ3R_p9wgwiB8Y1VHe9qz_9mHe2ZxDkjZK6IHjZ7RVyvQ https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcQoaakbzduBaygt_3gO3-x3sm2sgw45bXCKEEpH-jDrMAo2KnAB

Enrico Fermi

1942

Fermi was born on September 29, 1901 and died November 28, 1954. He conducted the first controlled chain reaction that released energy from an atom's nucleus. https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcTZ2bJ8pEh-0Unx6u-dz0vxmHqxwUznT60IqvDeZ2bbsXFqhwir https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcSDydVnAWnbnFCW2zzDmfzBUsjS5DJMPIRu1tjbE3nfu3JptPkL