Who discovered the atom and when?

Although J.J. Thomson is generally credited with creating the first proposed model of the atom, there were many scientists who also advanced the concept of the atom and the electron. Some of these scientists include Max Planck, John Dalton, Albert Einstein, Ernest Rutherford and Niels Bohr. read more

Though the word atom originally denoted a particle that cannot be cut into smaller particles, in modern scientific usage the atom is composed of various subatomic particles. The constituent particles of an atom are the electron, the proton and the neutron; all three are fermions. read more

Although scientists knew that atoms of a particular element have the same number of protons, they discovered that some of these atoms have slightly different masses. They concluded that the variations in mass result, more or less, from the number of neutrons in the nucleus of the atom. read more