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J.L. Gay- Lussac
Studied gas reactions at constant temperature
He noted that under constant conditions, the volume of reacting gases and gaseous products are in the ratio of small whole numbers -
Dalton
law of conservation of mass and definite proportions
If atoms cannot be destroyed, then atoms cannot be simply rearranged in a chemical change. The total number of atoms must remain the same. (September 3, 1803)
He believed that atoms were simpler than particles of air or rock. He also believed that all atoms of an element were exactly alike and that atoms of different elements were quit alike.Atoms can form in simple ratios to form compounds.
He was trying to explain the findings of Lavoisier a -
Amadeo Avogadro
Used Dalton's theory.
His hypothesis concerned gases at the same temperature and pressure
He stated that equal volumes of gases under the same conditions have the same number of molecules -
Henry Becquerel
He found that matter containing uranium exposes sealed photographic film -
J.J. Thomson
Did research on cathode rays
Credited with the result that cathode rays consist of electrons.
He built a cathode ray tube to subject the rays of both a magnetic field and an electrical field
He measured the bending of the path of the cathode rays and was able to determine the ratio of an electron's charge to its mass -
Marie Curie and Pierre
After Henri Becquerel found out about the films, they discovered that rays are given off by the elements uranium and radium. -
Albert Einstein
Made the equation E=mc2:
explains the origin of the energy released during nuclear changes -
Lord Rutherford
Brought together a team of physicists
He worked with Niels Bohr, Hans Geiger, and Ernest Marsden
They tried to shoot a positively charged stream of subatomic particles onto a thin sheet of gold.
They found that atom was mostly empy space
and few particles are deflected at large angles -
Henry Moseley
He studied X rays produced by x ray tubes with anodes of different metals.
He said that the number of protons determines the identity of the element and the number of nuetrons determines the particular isotope of the element -
Niels Bohr
Developed an explanation of atomic structure that underlies regularities of the periodic table of elements. His atomic model had atoms built up of sucessive orbital shells of electrons. -
Werner Heisenburg
Described atoms by means of formula connected to the frequencies of spectral lines. Proposed Principle of Indeterminancy - you can not know both the position and velocity of a particle -
Cockcroft and Walton
Built an early linear accelerator and bombarded lithium with protons to produce alpha particles -
Max Born
German Physicist
He worked with the square of the absolute value of the amplitude. He showed that it gave the probability of finding the electron at the point in space for which the equation was solved.
The probability is also the ratio between the number of times the electron is in that certain position and total number of times it is at all possible positions -
Erwin Schrodinger
Developed a mathematical equation to describe its wave like behavior
Terms for the total energy and for the potential energy of the electron are also part of this equation -
Wolfgang Pauli
Made the Pauli exclusion principle
No two electrons in an atom have the same set of four quantum numbers
