Scientists and Atoms
by Anna Sasek
Aristotle's atomic theory
Aristotle was born in 384 BC Instagira, Greece. He studied a lot of science it included logic, philosophy, ethics, physics, biology, psychology, and politics. His theory was that all substances were made of fire, water, air, and earth. He also thought that there were not tiny particles in atoms.
Dalton's Atomic Theory
Dalton made a living by teaching and researching science in his spare time. His experiments were investigating pressure and other properties of gases. Dalton's atomic theory had three parts protons, neutrons, and electrons. He believed that atoms were the smallest part of matter so he compared them to hard spheres.
Bohr's Atomic Theory
Bohr published his model of atoms in 1913. He thought his model was useful because atoms are in everything and electrons move around the nuecleus. With more energy it will jump to a higher level.
Mendeleev was a chemist he made the periodic table to sort out elements. He worked on organizing elements and he used a deck of cards so it would be easier for students to learn. He organized them by atomic mass witch that is an element. People did not believe Democritus because there was no way to test his answer. They believed Dalton's theory because he had some back up data.