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460
Democri'tus
Democri'tus, was an Ancient Greek philosopher. He was born in the year of 460BC in Abdera, Thrace, Greece. Democri'tus created theories that everything is composed of "atoms." He also stated that between atoms lies empty space, and that atoms have always been, and always will be in motion and indestructible. Democri'tus also belived that matter was made up of four basic elements. (Earth, air, fire, and water) -
John Dalton
John Dalton, an English chemist, physicist, and meteorologist proposed the Atomic Theory in 1803 . He was best known for his pioneering work in the development of the atomic theory. Dalton pictured atoms as very tiny particles, with no internal structure. -
Joseph John Thomson
British scientist, J.J. Thomson discovered the electron, and isotopes. J.J also invented his "plum-pudding" model, and the mass spectrometer. In his eyes electrons embedded in a sphere of positive eletric charge. -
Max Planck
Max Planck was a German physicist. Max discovered that energy travels in small packets, called quantum. He later made up the Quantum theory, which later helped Bohr come up with and addition to lord Rutherfor's atomic model. -
Hantaro Negaoka
Hantaro Negoka was a Japanese physicist. He suggested that atoms have central nucleuses. Nagaoka's atomic model was based on electrons revolving around the positively charged center of the atom like the rings of Saturn. -
Ernest Rutherford
Ernest Rutherford, was the fourth child in his family. He also was a British chemist and physicist. He discovered that electrons move randomly in the space around the positivley charged nucleus. -
Niels Bohr
Niels Henrik David Bohr was a Danish physicist. He was also known as one of the most influential scientists in the 20th. century. Bohr stated that electrons move in orbits at fixed distances from the nucleus. -
Erwin Schrodinger
Erwin Schrodinger, was an Austrian physicist. He developed mathematical equations to describe the motion of electrons in atoms. Later his work leaded to the electron cloud model. -
Henry Moseley
Henry Moseley was a English physicist. He discovered the atomic numbers, or elemental numbers. Moseley's discovery showed that atomic numbers weren't assigned, but rather, they have a strong physical basis. -
Ernest Marsden
Sir Ernest Marsden, was a English-New Zealand physicist. Ernest and Hans Geiger conducted the famous Geiger-Marsden experiment called the gold foil experiment in 1909 under Rutherford's supervision. The Geiger-Marsden experiment was an experiment to probe the structure of the atom. -
James Chadwick
James Chadwick, was a British physicist. He was awarded for his discovery of the neutron, which have no charge. Atomic nuclei contain neutrons and positively charged protons. -
Louis de Broglie
Frenchman Louis de Broglie, was a French physicist and a Nobel laureate. He was also known for wave nature of electrons. Louis stated moving electrons have properties of waves. Evidence collected a few years later supported his theory. -
Aristotle
Aristotle was a Greek philosopher, and polymath. He was born in the year of 384BC in Stageira, Chalcidice. Aristotle didn't do any experiments, but Aristotle's theories prevailed basically because people liked his philosophy better. He claimed that there was no smallest part of matter and that different substances were made up of proportions of earth, fire, air, and water.
