Chemistry Unit 3 (People)

John Dalton

Composed "Atomic Theory" -Showed that common substances always broke down into the same elements in the same proportion. -Concluded varies compounds were combinations of atoms of different elements, each of a particular size and mass that could neithr be created or destroyed.

Chadwick (Worked with Rutherford)

Developed the Neutron -Confirmed that along with the protons inside the nucleus, there were also matter that was neutral in change

JJ Thomson

Developed the electron -Showed how atoms are packed spheres of positive matter filled with negatively charged electrons.

Democritus

Developed the idea of an atom" (First proposed everything in the world was made up of tiny particles surrounded by empty space) -Called this "Atomos" (greek for invisble)

Niels Bohr

Expanded on Rutherfors nuclear model -He thought electrons orbited the nucleus at fixed energys and distances

Rutherford

Known as "father of nuclear age" -Conducted a research that was based on positively charged alpha particles at a sheet of gold foil -Concluded that atoms consisted of largely of empty space with just a few electrons, while most of the mass was consentrated in the center of the atom which he termed "the nucleus"

Aristotle

Matter was made of 4 elements. (earth, wind, fire, water)

Heisenberg

Showed it was impossible to determine both the exact position and speed of electrons as they moved around an atom.