-
Something we had to do for school.
-
Democritus - WikipediaTheorised that all matter was made up of atoms, and that each differed from each other in form, position and arrangement.
-
Newton - Scienceworld.WolframTheorised that different elements were made depending on the arrangement of the atom, and that atoms looked like small round billarad-like balls. He also theorised that atoms were held together by forces of attraction.
-
Dalton - WikipediaAtoms have a weight unique to an element and that all atoms of the same element are identical. Atoms can only be rearranged in a chemical reaction; not destroyed, created or separated into smaller particles. He came up with the Billard Ball model of an atom.
-
Stoney - UniversityscienceConcepted that electricity was made of negatively charged particles, later which he proposed to call electron.He also calculated the charge of an electron.
-
Thomson - ChemheritageFirst to discover electrons and isotopes. Proved the existance of subatomic particles through the use of cathode rays. Devised the plum-pudding model.
-
Planck - WikipediaExplained the glowing of hot matter with quanta; small discrete units of energy beging radiated from the matter. This lead to the quantum theory, revolutionising our study of the atom.
-
Nagaoka - WikipediaCreated the Saturian Model of the atom with rings of electrons around the nucleus; based on the planet, Saturn. Although many of the details were incorrect, it helped us understand the structure of an atom.
-
Milikan - JuliantrubinConducted the Oil Drop Experiment, and used it to determine the charge and mass of an electron.
-
Rutherford - Chemistry.aboutDiscovered alpha and beta decay in radioactive materials. Used alpha particles to probe the atoms in a thin piece of gold foil. Established that the nucleus was very small, dense and positively charged. He also hypothesised the existance of neutrons but assumed that electrons were found in the nucleus, giving us the Planetary or Nuclear model.
-
Moseley - ChemistryexplainedDetermined the charge of most nuclei using X-ray. Determined that an element's atomic number and number of protons were equal, leading to the Periodic Table of Elements being arranged by atomic number instead of atomic mass.
-
Bohr - WikipediaTheorised electrons travelled in orbit around the nucleus and created the Bohr Model of the atom after expanding on Rutherford's work.
-
Chadwick - AtomicarchiveDiscovered the neutron using alpha particles.
