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Democritus
He believed that there was small particle everywhere that couldn't be divided. He called these atoms which means "uncut." They say that Democritus didn't do any experiments to prove his theory. -
John Dalton
Dalton developed the theory to explain why elements in a compound always join in the same way. He got solid spheres and each type of atom represents a tiny sphere with different mass. -
Joseph John Thomson
Thomson used electric currents to learn more about atoms. He used a device that has a sealed glass tube, with metal disks at each end with wires connected to the source of electrical currents. Thomson thought it would show has a negative or postitive charge. His experiments provided the first evidens that atoms are mad of even more smaller particles. -
Neils Bohr
Bohr's model focused more on the electrons. Electrons is an atom that can move from one energy level to another when the atom gains or loses energy. Bohr's model was a similar look like our solar system, it had in the center the nucleus and moving around it was electorns. What he added to the atomic theory was that aorund an atoms nucleus there is electrons moving at a constant speed. -
Ernest Rutherford
He discovered that uraniumemits fast-moving particles that have a positive charge which he called them alpha particles. He aimed a beam of alpha particles at a piece of gold. More particles were deflected by 90 degrees. He dicovered that an atom has a central area that he called the nucleus. All of an atom's postitive charge is concentrated in its nucleus. -
Hantaro Nagaoka
Hantaro created a model based on the rings of the planet saturn. Although his model was incorrect, his model help us discover the rings of an atom. -
Albert Einstein
Albert made the theory of Relativity, which laid the basis for the release of atomic energy. He established a law of mass-energy through his formula E=mc to the second power. He calculates movement of moleculas in a liquid. -
Louis de Brogile
Louis said that moving particles like the electrons have some properties of waves. He says that the atoms do not move like the solar system like how Bohr's model show. He says they don't move in regular orbit as our solar system does. -
James Chadwick
Chadwick confirms that there is existances of neutrons and ended up nuclear physics. He would repeat his experiments over and over again to find neutral particles and he did. His theroy was that there was radioactivity. -
Aristotle
Aristotle didn't believe that there was a limit to the number of times matter could be divided. He made a model to describe matter. -
Ernest Marsden
Marsden worked with Ernest Rutherford and his experment n his theroy about the alpha particles. He went to Rutherford school and kept studing about the a particles and what they do. -
Hans Geiger
He became a valuable collaborators of Ernest Rutherford. He built the first version of jis particle counter, that led to the idebtification of the alpha particle as the nucleus of the helium atom. -
Erwin Schrodinger
Erwin developed an equation to describe the motion of electrons in atoms. Soon his work ended up leading to the electrons could model. He did all mathematical equations to solve his theroy about electron clouds.
