science quizwiz
JJ Thomson
Discovered the electron and noticed that an atom can be divided. Found that atoms are made of positive cores with negatively charged particles in them
Proton
Positive charge
Niels Bohr
Popularized the theory that electrons travel in orbit around the atom's nucleus. Introduced the theory that an electron with a higher energy orbit could drop to a lower one.
Ernest Rutherford
Proved that the atoms has a heavy, tiny nucleus. Suggested that the center might be proportional
John Dalton
Theorized that all matter is made of atoms. Every atom of a given element is identical in properties and mass. A compound is a mixture of two or more atoms. A chemical reaction is a rearrangement of atoms
Democritus
Theorized that everything was made of small, invisible particles called atoms. Said that atoms were solid and indestructible and the differ in size, mass and shape
Nucleus
The positively charged center of the atom
Electron
Negative charge
Neutron
Neutral charge