Boyle published his work and stated Boyle's Law in 1662 and was the first scientist to preform and present true quantitative experiments.
In the summer and all of 1771 Antoine contributed a lot of new information to the phenomenon of combustion
Discovered sulphur dioxide and oxygen gas
Discovered many new chemical elements such as: barium, manganese, molybdenum, tungsten, and phosphorus. Also discovered new compounds: citric acid, lactic acid, glycerol, hydrogen cyanide, hydrogen fluoride, and hydrogen sulphide
Proust’s largest accomplishment into the realm of science was disproving Berthollet with the law of definite proportions, which is sometimes also known as Proust's Law
Dalton's Atomic Theory:
Worked and added great amounts of new knowledge to how electricity passes through matter
Crookes invented the radiometer in 1875 and, beginning in 1878, investigated electrical discharges through highly evacuated "Crookes tubes." These studies laid the foundation for J. J. Thomson's research in the late 1890s concerning discharge-tube phenomena.
Modified Crookes' tubes and found that the rays inside the tube had a negative charge.
Discovered an isolated radioactive elements like uranium, radium, and polonium
Worked with Rutherford to understand and prove that the reason for the odd behavior of radioactive elements was because they decayed into other elements and created alpha, beta, and gamma radiation
Began research after Einstein published in 1905 and won the Nobel prize in 1926 for his definite proof of the structure of matter
Experiment that bombarded gold atoms with alpha-particles lead to Rutherford discovery of the nucleus
Won the Nobel Prize in 1908 for his discovery of the nucleus
Preformed oil-drop experiment and determined the charge and mass of a single electron
Co-inventor of the Geiger counter
Discovered the neutron, accounting for most of the mass in an atom