-
300
Aristotle
Aristotle seemed to work more the zoology and the topics of animals. This included making assumptions such as animals being classified by their way of life, their actions, or their parts. He also dealt with weather topics known as metaphysics. -
500
Democrtitus
Democritus was the first to determine that everything in the world is composed of atoms, and that atoms are the invisible. He came to the conclusion that the more invisible an atom is, the heavier it is. He reasoned that the solidness of the material corresponded to the shape of the atoms involved. -
Antoine Lavoisier
Antoine Lavoisier gave logical and more modern theories to the topics involving acids, bases, and salts. This helped more scientists to comprehend the scientific method and the process of other scientific studies. His understandings were a turning point in the scientific community as it helped a lot of people industially. -
Joseph Louis Proust
Joseph Louis Proust analyzed different compounds and concluded they always contained the same ratio by the weight of their element. This helped scientists fully understand more of the periodic table. A law was made that states that the ratio by mass of the elements in a chemical compound is always the same, regardless of the source of the compound. -
John Dalton
All matter is made of atoms, atoms are indivisible and indestructible, all atoms of a given element are identical in mass and properties, compounds are formed by a combination of two or more different kinds of atoms, a chemical reaction is a rearrangement of atoms. This is what Dalton concluded. -
Indivisible Solid Sphere Model
Discovered by John Dalton -
Michael Faraday
Faraday discovered electromagnetic induction, the principle behind the electric transformer and generator. He worked on developing his ideas about electricity. He was partly responsible for coining many familiar words including 'electrode', 'cathode' and 'ion'. -
Marie and Peirre Curie
Marie and Peirre spent their time examining the particles and energy produced as radioactive atoms decayed, and in the process learned about the building blocks of matter. They established that the heavy element thorium was radioactive and discovered two new elements: polonium and radium. -
J.J Thomson
J.J. Thomson discovered the electron as well as isotopes. When discovering electrons, he measured their speed and specific charge to conclude that they are 2,000 times smaller in mass compared to the hydrogen ion. He proved that isotopes could be broke by deflecting positive rays in electric and magnetic fields, which was later named mass spectrometry. -
Henri Becquerel
Created radioactivity. He accomplished this by researching newly discovered X-rays and that led to studies of how unanium salts are influenced by light -
Max Planck
Planck is the originator of the quantum theory. This theory revolutionized our understanding of atomic and subatomic processes. The discovery of Planck’s constant enabled him to define a new universal set of physical units. -
The Plum Pudding Model
Discovered by J.J Thomspson -
Albert Einstein
He applied the quantum theory (developed by German physicist Max Planck) to light in order to explain the phenomenon known as the photoelectric effect, by which a material will emit electrically charged particles when hit by light. The second article contained Einstein’s experimental proof of the existence of atoms, -
Ernest Rutherford
He was responsible for a remarkable series of discoveries in the fields of radioactivity and nuclear physics, discovered alpha and beta rays, set forth the laws of radioactive decay, and identified alpha particles as helium nuclei, and postulated the nuclear structure of the atom -
Planetary Model
Discovered by Ernest Rutherford -
Robery Milikan
proved accurate determination of the charge carried by an electron. He also proved that the charge was consisted for all electrons, it did not change. Deomstrated the atomic structure of electricity. -
Niels Bohr
Proposed that enegery is transferred only in certain well defined quantities, electrons should only move around the nucleus but only in a perscribed orbit, and when electrons are jumping from one orbit to another with a lower energy, a light quantum is emitted. -
Electron Cloud Model
Discovered by Niels Bohr -
Lise Meitner
Worked together with Otto Hahn to discover element protactnium. She also woekred with Hagn on his nuclear fission discovery. Meitner published the physical explanation for the observations for nuclear fission. -
Erwin Schrödinger
Schrödinger began to think about explaining the movement of an electron in an atom as a wave. He based his work off of Niel Bohr. His equation soon became to be known as Schrödinger's wave equation. -
Quantum Mechanical Model
Discovered by Erwin Schrödinger -
James Chadwick
Chadwick discovered the neutron. He did this by observing reactions and seeing that there was a neutral atom with the mass like a proton was present. -
Otto Hahn
Hahn is known best for his discovery of the fission of heavy nuclei. He was in the field of nucliear chemistry. He is also called the "father of nuclear chemistry". He discovered nuclear fission -
Glen T. Seaborg
He was the co-discoverer of plutonium and all further transuranium elements through element 102. He and his team are responsible for more that 100 isotopes of elements throughout the Periodic Table. -
Louis de Broglie
He did work on the quantum theory. He discovered the wave nature of electrons and suggested that all matter have wave properties. Broglie’s theory resolved and offered an explanation to a question that was brought up by calculations of the motion of electrons within the atom. involved X-rays, which made him think about the dual nature of light; more particularly the wave–particle duality.
