The Atomic Theory

He is best known for introducing the atomic theory into chemistry.

• John Dalton

• Marie Curie

• Pierre Curie

• Democritus

He was best known for his discovery of the law of definite proportions in 1794, stating that chemical compounds always combine in constant proportions.

• Earnest Rutherford

• J.J. Thomson

• Joseph Proust

• Rafael Abrigonda

He was credited with the discovery of the electron, the first subatomic particle to be discovered.

• Pierre Curie

• J.J. Thomson

• Johnny Depp

• Earnest Rutherford

Known for his work on the photoelectric effect or oil drop experiment.

• Earnest Rutherford

• Miguel Milkita

• Sigmund Freud

• Robert Andrews Millikan

A French engineer, physicist, Nobel laureate, and the first person to discover evidence of radioactivity.

• Pierre Curie

• Antoine Henri Becquerel

• Mark Villar

• Marie Curie

Known for the discovery of radium and polonium, and her huge contribution to finding treatments for cancer.

• Pierre Curie

• Marie Curie

• Democritus

• Radium Smith

He/she discovered alpha and beta rays, set forth the laws of radioactive decay, and identified alpha particles as helium nuclei.

• Pierre Curie

• Ernest Rutherford

• R.A. Millikan

• Omega Thomson

This scientist proved the existence of neutrons – elementary particles devoid of any electrical charge.

• James Chadwick

• J.J. Thomson

• Chadwick Boseman

• Marie Curie

An Ancient Greek pre-Socratic philosopher primarily remembered today for his formulation of an atomic theory of the universe.

• Leviticus

• James Chadwick

• Pierre Curie

• Democritus

His gold foil experiment showed that the atom is mostly empty space with a tiny, dense, positively-charged nucleus.

• John Dalton

• Earnest Rutherford

• John Matthews

• J. J. Thomson