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Democritus
discovered the first atom theory. He believed that everything is made of tiny things that never get deleted, they can only be moved or changed. -
Antoine Lavoisier
performed his twelve-day experiment in 1779 which has become famous in history. He heated pure mercury in a swan-necked retort over a charcoal furnace for twelve days. A red oxide of mercury was formed on the surface of the mercury in the retort. When no more red powder was formed, He noticed that about one-fifth of the air had been used up and that the remaining gas did not support life or burning. -
Law of consevation of mass- Antione Lavosier
States that mass is neither created nor destroyed in any ordinary chemical reaction. This was also discovered by antione lavosier. in 1789 almost 10 years after his first. -
John Dalton
Responsible for the basis of the atomic theory. He mad the BILLARD BALL MODEL. Which states that all matter is composed of extremely small spatricles called atoms. -
Daltons Atomic Theory
First he though All matter is made of atoms. Atoms are indivisible and indestructible.Secondly he said All atoms of a given element are identical in mass and properties
Next he said that Compounds are formed by a combination of two or more different kinds of atoms. 4) A chemical reaction is a rearrangement of atoms. -
Dmitri Mendeleev
He is the father of the modern periodic table. Which he predicted the properties of undiscovered elements. -
Cathode Ray Tube
This is an electric current inside a sealed tube must be negitavely charged and present in all elements. Since atoms are neutral they must also contain some positive charge. -
JJ Thomson
He discovered the electron. He determined the mass to change the rtio of a particle. He was the doscoverer of the plum pudding atomic model -
Plum Pudding Atomic Model
the atomic structure consisted of just a bunch of electrons floating around in a positively charged goo of sorts that balanced the negative charge of the electrons. It was later shown to be false when Rutherford and his colleagues performed the famous gold foil experiment and "discovered" the nucleus was a concentrated mass of positive charge rather than a spread out soup. -
Robert Milikan
THis man determind the mass of an electron -
Rutherford Model
d. The nucleus is thusly positively charged and makes up virtually all the mass of the atom. It goes on to say that in the atom this nucleus is surrounded by an electron cloud, some 100000 times bigger than the nucleus, which contains tiny negatively charged electrons that orbit the nucleus in a similar manner to how the planets orbit the sun in the solar system. -
Henry Mosley
using x-ray spectra obtained by diffraction in crystals, he found a systematic relation between wavelength and atomic number, Moseley's law. In other words he used x rays to determine atomic numeber -
Bohr Plantary
he negatively-charged electrons orbit a small, positively-charged nucleus similar to the planets orbiting the Sun -
Niels Bohr
a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922 -
Gold Foil Experiment
absorption of radioactivity by thin sheets of metal foil and found two components: alpha radiation, which is absorbed by a few thousandths of a centimeter of metal foil, and beta radiation, which can pass through 100 times as much foil before it was absorbed -
Erwin Schrodinger
Erwin discovered the electron cloud model theory and made the schrodinger equation which is the foundation for the quatum mechanics in its wave formation -
Quantum Mecahnical Model
The Bohr model shows electrons in neat, planet-like orbits around the nucleus. though it is incorrect it is still used to show different things. as in the plantes that orbit the sun -
Ernest Rutherford
He discovered what was inside an atom, putting paid to the previously accepted "plum pudding" model. By setting up a classic experiment involving gold foil and an alpha particle emitter, he noticed that atoms consisted of a dense central region Which had a positive charge. -
James Chadwick
james chadwik discovered the neutron. A neautron does not have charge. He said atoms are sphereically shaped nd have a tiny nucleaus with a positive charge. -
Electron Cloud Model
a visual model of the most probable locations of electrons in an atom. The cloud is denser where you will probably find an electron. The electron cloud model is used to describe the possible locations of electrons around the nucleus.
The electron cloud model was developed by Erwin Schrodinger by using matematical equatiuons to describe the motion of electrons in atoms.
