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John Dalton
John Dalton (English chemist, physicist and meteorologist, 1766- 1844) discovered that all atoms are solid and with a measurable mass and cannot be divided. His theory was that all gasses were made of atoms and those atoms had set weights. He came upon the idea of the chemical combination of particles because he assumed that particles combined in the simplest possible ways. John hypothesized that you could count the number of atoms in a compound and represent these as integer ratios. -
J.J.Thomson
J.J Thomson (Full name Joseph John Thomson, British physicist, born 1856, died 1940) was most acclaimed for his discovery of the electron in 1897. In 1904 he hypothesized that an atom is a sphere with positive charge and has negatively charged electrons around it, put there by electrostatic forces. He did his all through many complex experiments, and eventually could calculate the ratio of mass to charge and later even estimate the value of the charge. -
Marie Curie
Marie Curie (French-Polish physicist and chemist, lived 1867-1934) discovered two new elements - polonium and radium - studied uranium radioactive waves and invented a new way for separating radioactive isotopes.The work she did with radioactivity was very dangerous and physically demanding. She was acclaimed in may ways for the progress of the scientific world; she was the first woman to win a Nobel Prize and very first person to win in two different sciences. -
Ernest Rutherford
Ernest Rutherford (British physicist and chemist, lived 1871-1937) is known for his atomic theory of the atom has a central nucleus which is positively charged orbited by negatively charged electrons. This suggested that the atom’s mass was only the weight of a small nucleus, while the remaining part of the atom was mostly empty space. He is also known for his famous Gold Foil experiment, through which he discovered Rutherford dispersion. -
Henry Moseley
Henry Moseley (British physicist, lived 1887-1915) observed the spectra of X-Ray electromagnetic radiation that was produced by diffracting it through crystals. He found that there was a systematic relation between the atomic number and the wavelengths produced. His discovery and conclusions lead to a better and clearer organization of the Periodic Table of Chemical Elements. He predicted a number of elements on the table as well that had been missing and even figured out their periodic numbers. -
Francis Aston
Francis William Aston (British chemist and physicist, lived 1877-1945) was most acclaimed for his discovery of isotopes, which are the same elements in chemical properties but not in atomic mass, and also for his demonstration and expression of the ‘whole number rule’. This rule bacically states that integer multiples of the hydrogen atom mass are masses of isotopes. -
Niels Bohr
Niels Henrik David Bohr (Danish physicist, lived 1885-1962) tremendously contributed to atomic structure and quantum mechanics. His model of the atomic structure became the basis of our current understanding. He said that electrons were trapped in set and clear orbits around the nucleus, that they could go between orbits but nowhere outside of the set paths and that an electron absorbs or emits certain amounts of energy as it moves from set orbit to orbit. -
Erwin Schrodinger
Erwin Schrödinger (Austrian physicist, lived 1887-1961) formulated the wave equation through his advanced studies of quantum theory. This is crucial to our understanding of light and behavior of subatomic particles. Combining the equations of wave behavior, he created a mathematical model of an atom with mathematical equations and functions that place electrons in their positions. He discovered how to calculate the distribution of electrons in an atom, the 3D size of their of their orbit. -
James Chadwick
James Chadwick (English Physicist, lived 1891-1974) was mistakenly admitted in a physics course in Victoria University rather than the mathematics course he was interested in, but this lead to proof of the existence of the neutron. He did this by exposing a nitrogen particle to radiation and drawing conclusions of the reaction. He was one of the first to use a very direct method to determine the electrical charge of the nucleus. -
Murray Gell-Mann
Murray Gell-Mann (American physicist, live 1929-present) came up with the concept of quarks and did a lot of work on describing and classifying subatomic particles. He hypothesized that there was a way to elaborate the set properties of particles in the way of basic particles. He called the fundamental particles ‘quarks’, a number of subatomic particles that are assumed to be what make hadrons.
