History of the Atom

He was born in Abdera, Greece. His mentor, Leucippus, originally came up with the atomic theory, but it was then adopted by Democritus. The atomic theory stated that “The universe is composed of two elements: the atoms and the void in which they exist and move.” According to Democritus atoms were miniscule quantities of matter. Democritus hypothesized that atoms cannot be destroyed, differ in size, shape and temperature, are always moving, and are invisible. He believed that there are an infinite number of atoms. This hypothesis was created in 465BC. He published over 70 books.
Born to a family of wealth. Democritus had no technology available to him and did not conduct any experiments to test his ideas. He had no proof that atoms existed and no evidence to back up his claims. He left it to later scientists to prove or disprove his ideas.

He was from France. He was known for his experimentation skills. One of his favorite experiments being turning HgO into Hg+O. He used this experiment to help himself come up with the Law of Conservation. The law states that matter cannot be made or destroyed. He also hints at the rearrangement of matter in reactions. Matter rearranged, but never disappeared. In experiments with phosphorus and sulfur, both of which burned readily, Lavoisier showed that they gained weight by combining with air. With lead calx, he was able to capture a large amount of air that was liberated when the calx was heated.
He was a French nobleman who is considered to this day to be the father of modern chemistry. His work was crucial in a period of discovery that is now known as the Chemical Revolution, or even the First Chemical Revolution.

He is from Cumberland, England. His atomic theory said that elements consisted of tiny particles called atoms. It states an element is one of a kind (aka pure) because all atoms of an element are identical. All the atoms that make up the element have the same mass. All elements are different from each other due to differing masses. He experiments with gases that first became possible at the turn of the nineteenth century led John Dalton in 1803 to propose a modern theory of the atom based on the following assumptions. When John Dalton died, 40,000 people attended his funeral procession.
He discovered color blindness, and still today it is sometimes referred to as "Daltonism".

He was from Keil, He worked in thermodynamics and led to the formulations of his quantum theory. To explain the colors of hot glowing matter, he said that “energy is radiated in very minute and discrete quantized amounts or packets, rather than in a continuous unbroken wave”. Planck called the packets of energy quanta and he was able to determine that the energy of each quantum is equal to the frequency of the radiation multiplied by a universal constant that he derived, now known as Planck's constant. It is used to describe the behavior of particles and waves at the atomic scale. Planck announced his findings in 1900, and in 1905, Albert Einstein used Planck's quantum theory to describe the particle properties of light. Einstein demonstrated that electromagnetic radiation, including light, has the characteristics of both a wave and, consistent with Planck's theory, a particle. These particles were later called photons. In 1913, Niels Bohr used Planck's theories to develop a new and more accurate model of the atom. Planck made significant contributions to science throughout his life.

She was born in Warsaw, Poland. She traveled to Paris to continue her studies in getting her Licentiateship in Physics and Mathematical Sciences at the Sorbonne. In 1894 she met Pierre Curie, her husband, who was the Professor in the School of Physics. Pierre was the head of the Physics Laboratory at the Sorbonne. In 1903, Marie obtained her Science degree and three years later her husband Pierre died, leaving her the position of professor of General physics. This was the first time a woman had held this position. In 1914, Curie was appointed Director of the Curie Laboratory in the Radium Institute of the University of Paris. Here, Marie developed methods to separate radium from radioactive resides. This allowed careful study of the characterization. It was used for therapeutic properties. President Hoover gave her a grant of $50,000 to purchase radium. She was also a member of the Conseil du Physique Solvay at this time until 1922. She received many awards and honors for her scientific ideas and discoveries. Including two Nobel Prizes, Davy Medal of Royal Society, and her daughter won the Nobel Prize in 1935, being the first mother and daughter to share the honor. She was the author of Recherches sur les Substances Radioactivies in 1904, L’lsotopie et les Elements Isotopes and Traite de Radioactivite in 1910. Her awards were won and papers were written on how she isolated one-tenth of a gram of pure radium chloride from eight tons of pitchblende residue. This required much physical labor. She also determined the atomic weight of radium to be 225. Marie Curie died in Savoy, France, after a short illness, on July 4, 1934. She is referred to as the “mother of atomic physics" and is a legend of the twentieth century science. We now know that radium is toxic and should not be handled. However, it is used to fight cancer and in other forms of medicine.

He was from Morrison, IL. Robert Millikan contributed to the atomic theory in his own way. Using Thomson’s electron results, he conducted his own experiment, which he called the oil drop method. By conclusion, Millikan confirmed Thomson’s theory.

He was from Brightwater, New Zealand. Ernest Rutherford described the atom as having a central positive nucleus surrounded by negative orbiting electrons. This conclusion was gathered from using the gold and foil experiment, which involved the firing and radioactive particles through thin metal foils and espying them by using screens coated with zinc sulfide. He found out that although most of the particles passed through the foil, 1 in 8000 bounced off, which lead him to the theory that most of the atom was made up of empty space.

He was born in Ulm, Germany, Using Brownian motion, Einstein was able to accurately calculate the average distance an immersed visible particle would travel in a given time. His mathematic laws governing the movements of invisible particles could be tested and measured by observing the motion of the visible simply using a microscope and a stopwatch. Although this was a very difficult to test a hundred years ago, eventually Einstein’s calculations were fully confirmed by Jean Perrin in 1909, winning Perrin the Nobel Prize.

He is from Copenhagen, Denmark. Niels Bohr added onto Rutherford’s theory with his own model. His interpretation was that electrons orbited the nucleus of an atom in pre-defined energy levels, and if the energy level was dropped, they would emit a photon. This is how the basis of quantum theory was formed

He is from Vienna, Austria. Erwin Schrodinger built onto Bohr’s model of the atom with the electron Cloud Model. Of which interpreted the floating motion of the electrons, instead of having a set path for them to travel. He figured the likelihood of the location of the electrons in atoms. According to Schrodinger, Orbitals are areas of space around the nucleus in an atom.