Atomic Structure: Protons, Neutrons, and Electrons

Atomic structure is built from three subatomic particles: protons, neutrons, and electrons. Atoms make up all matter, and these particles explain an atom’s mass and charge.

The electron was first identified at the end of the 19th century by J.J. Thomson. He used a cathode ray tube, a sealed glass...

Dalton’s atomic theory naturally led to the question of whether atoms themselves are divisible. A series of subsequent experiments demonstrated that an atom is in fact made of three fundamental particles called the subatomic particles – electrons, protons, and neutrons.

Electrons were discovered by J.J. Thomson, when he observed a beam o...