Timeline of Atomic Theory

A French chemical physicist who was a pioneer in the development of x-ray techniques. She was the first to observe weak emissions in gases (1934) and also established energy levels of an atom, singly or multiply ionized from an inner shell. Which connects greatly to the atomic theory and ultimately lead her to proving the existence of rare elements like polonium and astatine. Despite the inequalities towards women in her time, she persevered to prove her theory.

Ida Tacke was the first official German chemist and physicist. She was also the first to suggest the concept of nuclear fission and co-discovered the element rhenium 1934. Her work was ignored due to sexism, and she was nominated for the Nobel Prize in chemistry 3 times.

Hantaro Nagoka was a Japanese physicist who worked as a professor at the university of Tokyo. He contributed towards the understanding of the atomic theory and his two major predictions were that atom's have a very massive center and electrons revolve around the nucleus attracted by electro static force. He was granted the award "Order of Culture" by the Japanese government in 1937, however went unnoticed in his contributions towards the understanding of atomic structure.

Lise Meitner was an Austrian-Swedish physicist who worked alongside famous chemist Otto Hahn. Being the second woman in the world to earn a doctorate in Physics, she contributed towards the understanding of elements and atomic theory through her partnering discovery of the element protactinium and nuclear fission in 1938. Due to sexism she was not awarded the Nobel Prize, however within her lifetime she was nominated 48 times and received other awards for her work in Physics.

German-born scientist who made it possible to understand how the nucleus of an atom works through developing the nuclear shell model in 1949. Her work was important to the development of nuclear and particle physics and her vast knowledge of mathematics lead her to this impressive step forward to understanding atomic theory. Due to the unfair disadvantages women had in the past, It took Maria Mayer a whole career to be recognized for her work with a Nobel Prize in physics.

Satyendra was an Indian mathematician and physicist. Specializing in the study of theoretical physics he collaborated with Einstein and developed the Bose-Einstein condensate theory, his work relates to the atomic theory because of some of his work being on atomic structure. He was eventually awarded the Padma Vibhushan (second highest civilian award) in 1954. He was noticed in India for his influential research however was not as known around the world for his work with Einstein.

Chien-Shiung Wu was a Chinese-American physicist involved in the Manhattan Project. She helped to develop the process for separating uranium into isotopes by gaseous diffusion. She also developed "Geiger counters" for measuring nuclear radiation levels. She moved to America for her PhD because it was easier for women there at the time. She won the 1957 Nobel Prize for Physics, however her work was underrepresented due to racism and sexism.

Christiane Bonnelle was a female physicist and spectroscopist who worked as a chemistry professor for most of her life at Pierre and Marie Currie university. Her work as a scientist related to the atomic theory through her achievements in surface science and the measurement of subatomic particles with the nanometer. In 1967 she received a CNRS Bronze Metal, however went greatly unnoticed as a valued contributor to modern chemistry.

Gerhard Herzberg was a German-Canadian physicist known for discovering electronic structure and the geometry of molecules. His atomic theory related work consisted of a variety of research on free radicals, diatomic molecules and molecular structure etc. Being a very influential Canadian scientist, he was awarded with the 1971 Nobel Prize for Chemistry, and provided the founding work that started the study of molecular spectroscopy.

Richard Bader was a Canadian quantum chemist known for his discovery that electron density is needed to explain the behavior of atom's in molecules in the late 1970's. His work related to the atomic theory because his focus as a quantum chemist was on the behavior of atom's in molecules. Unfortunately his work contradicted the accepted theories at the time... Eventually, his theory became more accepted and he published his book "Atoms in Molecules, a Quantum Theory" in 1991.

Henry Taube was a Canadian-German immigrant mentored by Gerhard Herzberg. His work as a chemist contributed towards atomic theory through his research on how electron transfer impacted the rate of chemical reaction in metals. Essentially bringing his ideas from organic chemistry into inorganic chemistry. He did not go unnoticed as a talented chemist, and won the 1983 Nobel Prize in Chemistry.

Rudolph Arthur Marcus was a Canadian chemist who studied at McGill. His work related to the atomic theory through his developed theories on how atoms could swap electrons and how electron transfer was involved in chemical reactions. He later moved to the United States where he continued his work as a chemistry professor at the University of Illinois. He received the 1992 Nobel prize in chemistry, and is known to this day for the "Marcus theory of electron transfer".