-
Jan 1, 1178
Law of Conservation of Mass
States that mass is neither created nor destroyed in any ordinary chemical reaction, or more simply, the mass of substances produced (products) by a chemical reaction is always equal to the mass of the reacting substances (reactants). -
Democritus
Says "These atoms are eternal and invisable." They are absolutely so small that they can't get any smaller. -
Antoine Lavoisier
Perceiving that in combustion and the calcination of metals only a portion of a given volume of common air was used up. Also known as "non-vital air". -
John Dalton
Since he was color blind it as hard for him to see the colors that were coming out of his experiment. He suggested that a chemical combimation consists of a number of atoms definite and characteristc weights. -
Dmitri Mendeleev
He created the original work covered a wide range, from questions in applied chemistry to the most general problems of chemical and physical theory. -
Electron Cloud Model
Function basically describes a cloud-like region where the electron is likely to be found. -
J.J Thomson
Invented the Plum Pudding method. In the cathode ray tube the particles that are being produced are negatively charged. -
Cathode Ray Tube
Designed by Ernesto Rutherford. He says that, "What was then the world's most sensitive electromagnetic wave detector." -
Ernest Rutherford
He showed that radioactivity is a manifestation of sub-atomic change. -
Robert Millikan
He measured the electric charges on tiny falling water (and later oil) droplets. -
Plum Pudding Atomic Model
The components of the atoms have been discovered. Consists of a subatomic particles called protons and electrons. -
Rutherford Model
Describing the atom as having a central positive nucleus surrounded by negative orbiting electrons. -
Bohr Planetary Model
His theory elaborated and expanded by other physicists, formed the basis for the developing science of quantum mechanics. -
Henry Moseley
Which correlated wavelength and atomic number, thus demonstrating the importance of atomic number over atomic weight, as was the common belief. -
Niels Bohr
Bohr's atomic diagram held that the outer orbits hold more electrons than the inner orbits. -
Erwin Schrodinger
He introduced the "Schrondinger's wave" a mathmatical equation of wave mathmatics. -
James Chadwick
He proved the existence of nuetrons and also a fundamental building block of the atoms nucleus. -
Dalton's Atomic Theory
Rationalised the various laws of chemical combination which were in existence at that time. However, he made a mistake in assuming that the simplest compound of two elements must be binary, formed from atoms of each element in a 1:1 ratio -
Quantum Mechanical Model
Defines the electrons as moving along set orbits around the nucleus.
