Matter was composed of atoms that could be divided no further
atomos= greek for indivisible
LavoisierMade measurements of chemical change in a sealed container
Found law of conservation of mass (matter): when a chemical reaction occurs, mass is neither created nor destroyed but only changed.
ProustRegardless of the source of Water it always contain these same percentages of Hydrogen(11%) and Oxygen(89%).
Daltondalton Atomic TheoryAtomic Theory:
1. Matter is composed of tiny indivisible particles known as atoms
2. Atoms of the same element are identical and atoms of any one element are different from those of another element
3. Law of Conservation of Mass: Reactions occur when atoms are seperated from one another, joined or rearranged but matter can not be created or destroyed.
4. Atoms of different elements can combine in whole number ratios to form compunds.
Law of Definite Proportion
Law of Multiple Proportion
J.J. ThomsonPlum Pudding
Created the cathode ray tude
Electrons- negitivitly charged particles
Protons- positively charged particles
Plum Pudding Model: electrons surrounded by a soup of protons, like negatively-charged "plums" surrounded by positively-charged "pudding"
In the gold foil expeiment, Rutherford correctly deducted that most of the remainder of the atom was empty space. Rutherford termed his discovery "the central charge" later named the nucleus.
MilikanOil Drop Experiment
He created the oil drop experiment. From the oil drop experiment he determinded the charge of the electron. His conclusion was the mass of one electron is 1/840 the mass of a proton essentially the electron has no mass.
Chadwick won the 1935 Nobel Prize in Physics.
He proved the existence of the neutron.
Chadwick's later experiments with particle accelerators contributed to the invention of the nuclear fission bomb.