The History of the Atomatom.jpg

>The solid model of an atom was one which suggested that an atom is a more than a singular, solid particle having no other compoents.>The Planetary Model of an atom in which, there is a representation with the positively charged nucleus in the center, having the negatively charged electrons orbiting in seperate paths around the nucleus.
A stylized representation of a lithium atom.
A stylized representation of a lithium atom.

Ancient World Events
776 B.C- First Olympic Games
750-700 B.C- Homer writes the Iliad and The Odyssey
671-667- Assyrians incade Egypt "sacking" Thebes and Memphis

Anaximander 610-546 B.C( Born in Miletus) anaximander.jpg
Anaximander was the author of the first surviving lines of Western Philosphy. He was the first speculative astronomer. He made the wide picture of the open universe, replacing closed universe of the celestial vault. He came up with the idea that the first principle isn't any of the elements water,fire,air or earth, but that it was intermediate and had no characteristics. It is before and further than all distinctions in being, such as it cannot be limited by anything, in the sense of being conditioned by something.

Democritus ~470 to 380 B.C(Born In Greece)dcritus.jpg
Democritus came up with the theory that anything and everything is made up of extremely small unreducilble particles called Atoms, in 400 B.C.
"Nothing exists except atoms and Empty Space. Everything else is Opinion."

Aristotle 384 to 322 B.C(Born In Greece)aristotle3.jpg
Aristotle came up with the original Scientific Method containing four causes/ questions involved in the whole process. The categories of this original method were single words compared to propositions. They included the following 10, substance, quantity, quality, relation, place, time, situation, condition, action, passion. They would be arranged simply in the order of the way that you would ask each question. He came up with this method near 350 B.C.

Robert Boyle 1627-1691(Born in England)aalcimizm_clip_image008_0001.jpg
Robert Boyle extended the subject of mathematics further more into chemistry, he also successfully revived the atomic theory.

World Events between 500-1800
1325- Aztecs founded Tenochtitlan (now Mexico City)
1607- Jamestown Colony, first english permanent settlement in Virginia
1754-1763- Anglo-French War in North America

Antoine Lavoisier 1743-1794(Born in France)

In 1777 he demonstrated the Conservation Of Matter( that being, Matter cannot be created nor can it be destroyed), in a chemical reaction.Then used this to help him state the difference between an element and a compound.


Charles Coulomb 1736-1806(Born in France)

In 1780 he described the force betweeen two electrical forces with a mathematical equation (looking similar to Newtons Law of Gravity).
F= (Q1 times Q2) divided by (r squared)


Rene Hauy 1743-1822(Born in Oise)

He formulated the first laws of crystal structure. He classified minerals by characteristic arrangements instead of using chemical properties, this work being the base of modern crystallography. *


Philosophers during 1800-1900
World Events between 1800-1875
1806- Napoleon brings the holy roman empire to an end
1830- Revolution in France
1833- Abolition of slavery in Britain

World Events between 1875-1900
1878- Congress of Berlin ends Russo-Turkish War
1879-1884- The War of the Pacific between Peru, Chile and Bolivia
1898- Spanish-American War

John Dalton 1766-1844( Born in England)

John Dalton modernized the atomic theory in 1803. His model showed that all atoms in any given chemical is the same as another atom in that same chemical. The model also helped him show that the atoms of different elements are different from one another judging by their atomic weight.


James Clark Maxwell 1831-1879 (Born In England)amaxwell.jpg

In the 1860's He came up with the connection between electricity and magnetism and that they are two aspects of the same great thought. With this he also predicted accelerating charges radiate waves at the speed of light. These waves came to be known as electromagnetic waves, for example visible light.

Wilhelm Conrad Rontgen 1845-1923 (Born in Germany)

In 1895 he used, not knowing at the time, the help of his wifes hand to discover the first form of an X-Ray. He showed that the new rays are produced when there an is an impact on a material by a cathode ray.


Henri Becquerel 1852-1908 (Born in France)Becquerel.gif
In 1896, he discovered the phenomenon of natural radioactivity. He decided to take Rontgens discovery of the X-Ray and see if there was ne connection between that and naturally occuring phosphoresence.

J.J Thomson 1856-1940 (Born in England)jj_c1890.jpg
In 1898, he discovered the electron, that being the part of an element being negatively charged. He showed his discovery through a model, The Plum-Pudding Model, which had negatively charged particle spread out evenly throughtout a circle of evenly charged material.


Marie Curie 1867-1934 (Born in France)abmariecurie.jpg
In 1898, Madam Curie and her husband Pierre discovered two new radioactive elements, those two elements being Polonium and Radium.

World Events between 1900-1915
1901-1905- Seperation of the Church from the State in France
1912-1913- The Balkan Wars
1914- Panama Canal opened

Max Planck 1858-1947 (Born in Germany)aPlanck.jpg
In 1900 he introduced the quantum theory to explain the shape of the temperature versus the colored curve of a glowing solid. He also fell into finding out that light cannot be changed into heat.

Ernest Rutherford 1871-1937 (Born in England)aLord_Ernest_Rutherford_-_1908-357x480.png
In 1909 he showed that the atom is made up mostly of empty space with a small positively charged nucleus containing most of the mass and low mass negatively charged particles. He went on to experimentally identify nuclear particles with positive charges, that he went on to name as Protons. From his identification of the proton, he stated that there was a neutral particle with nearly the same mass as a proton, this particle became known as the Neutron.

external image Gold_Foil_Exp.jpg

Robert Millikan 1868-1953 (Born in USA)
His earliest major success was the accurate determination of the charge carried by an electron, using the elegant "falling-drop method"; he also proved that this quantity was a constant for all electrons (1910), this led to his discovery of the atomic structure of electricity.

Niels Bohr 1885-1962 (Born in Denmark)aNiels_Bohr.jpg
In 1913 he developed the first successful model of the atom, since then we still use Bohr's model to explain the many aspects of physical occuring such as the appearance of spectra. He helped fix a problem involving why the electron particles dont just fall down towwards the middle of the nucleus. He came up with the reason being that the electrons are confined to a specific orbit that were quantized, so even with the loss of energy the electrons stay in their orbit.

external image Bohr-planetary-atom-model.jpg

World Events between 1915-1950
1917- United States declares war on Germany
1945- US scientists build first Atomic Bomb; Drop first bombs on Japanese cities Hiroshima and Nagasaki
1947- India gains independence

Werner Heisenberg 1901-1976 (Born in Germany)HSwerner.jpg
In 1925 he developed the first version of Quantum Mechanics which was a matrix method of calculating the behavior of electrons and other subatomic particles.

Erwin Schrodinger 1877-1961 (Born in Austria)ahimage.jpg
Was involved in a wide variety of different subjects falling under theoretical physics. He dealt with heats of solids, problems of thermodynamics and the atomic spectra. In addition he was involved in physiological studies of Color. But his great discovery in 1926 was Schrodingers Wave Equation.

James Chadwick 1891-1974 (Born in England)
In 1932 he made an important discovery in the domain of Nuclear Science, he proved the existence of Neutrons, which he believed to be elementary particles devoid of any electrical charge.

World Events between 1950-Current
1963- President John F. Kennedy assasinated
1965-1973- Vietnam War
2001- Terrorist attacks on World Trade Center in New York